DOCSLIB.ORG

Thyrotropin-Releasing Hormone (Trh) Receptors

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Thyrotropin-Releasing Hormone (Trh) Receptors 0270.6474/85/0502-0551$02.00/O The Journal of Neuroscience Copyright 0 Society for Neuroscience Vol. 5, No. 2, pp. 551-561 Printed in U.S.A. February 1985 THYROTROPIN-RELEASING HORMONE (TRH) RECEPTORS Localization by Light Microscopic Autoradiography in Rat Brain Using [3H][3-Me-His2]TRH as the Radioligand’ PATRICK W. MANTYH* AND STEPHEN P. HUNT Medical Research Council Neurochemical Pharmacology Unit, Medical Research Council Centre, Medical School, Cambridge, CB2-2QH United Kingdom Abstract Thyrotropin releasing hormone (TRH) is a putative neurotransmitter in both the central and peripheral nervous system. In the present report, we have used autoradiography coupled with densitometric analysis of tritium-sensitive film to investigate the distribution of [3H][3-Me-His2]TRH ([3H]MeTRH)-binding sizes in the rat brain. Previous pharmacological reports have established that many of these [3H]MeTRH-binding sites have a structure-activity profile consistent with being a physiological TRH receptor. A high level of TRH receptors were observed in the accessory olfactory bulb, lateral nucleus of the amygdala, dentate gyrus, and entorhinal cortex. Moderate levels of TRH receptors were observed in the rhinal cortex, hypothalamus, superior colliculus, several brainstem motor nuclei, and lamina I of the spinal trigeminal nucleus pars candalis, while low concentrations of receptors are present in the cerebral cortex, striatum and ventral horn-of the spinal cord. Very low levels of receptors were observed in the globus pallidus and in most nuclei of the dorsal thalamus. Comparisons of the distribution of TRH receptors to TRH-immunoreactive content indicates that, while in some areas of the brain there is a rough correlation between levels of TRH peptide and its receptor, in most brain areas there is little obvious correlation between the two. While such a discrepancy has been observed for other peptides and their receptors, the extensive distribution of TRH receptors in the central nervous system does provide an explanation for the variety of behavioral effects observed when TRH is infused into the central nervous system. The tripeptide thyrotropin-releasing hormone (TRH, pGlu- (Sharif and Burt, 1983; Sharif et al., 1983), and some peripheral His-Pro-NH2) was originally isolated from the hypothalamus tissues (Burt and Snyder, 1975; Taylor and Burt, 1982). That of pigs and sheep and shown to act upon the anterior pituitary these TRH receptors are functional is suggested by electro- to evoke release of thyrotropin-stimulating hormone (Guille- physiological studies which have demonstrated that neurons min, 1978; Schally, 1978). Since this original isolation, it has responsive to TRH are found in cerebral cortex (Renaud and become apparent that thyrotropin release is only one of the Martin, 1975; Braitman et al., 1980), septum (Winokur and many actions of TRH. Using radioimmunoassay (Brownstein Beckman, 1978), hypothalamus (Renaud and Martin, 1975; et al., 1974; Jackson and Reichlin, 1974; Winokur and Utiger, Winokur and Beckman, 1978), cerebellum (Renaud and Mar- 1974; Kardon et al., 1977) and immunohistochemistry (Hokfelt tin, 1975), and the spinal cord (Nicoll, 1977). Behavioral data et al., 1975a, 1975b), TRH (Jackson, 1980) has been shown to also supports the hypothesis that TRH interacts with its recep- be present in both the CNS and in a variety of peripheral tors outside the hypothalamo-pituitary axis. Thus, TRH infu- tissues including the pancreas and digestive system (Morley, sion in the CNS has been shown to produce a pressor response 1979). Interestingly, the distribution of TRH receptors has (Beale et al., 1977), tachycardia (Hine et al., 1973), hyperther- been shown to be even more ubiquitous than the peptide TRH. mia (Metcalf, 1974), satiety (Vijayan and McCann, 1979; Mor- Using homogenate tissue binding, it was shown that TRH ley and Levine, 1980), locomotor activity (Vogel et al., 1979), arousal (Stanton et al., 1980), and to antagonize the effects of receptors are also present in the forebrain, brainstem (Burt and barbiturates and alcohol in the CNS (Kalivas and Horita, 1980). Snyder, 1975; Ogawa et al. 1981; Taylor and Burt, 1982; Si- Other more controversial reports have suggested that TRH masko and Horita, 1982), retina (Burt, 1979), spinal cord administration may be of therapeutic benefit for patients af- flicted with depression (Kastin et al., 1972; Prange et al., 1972; ’ We would like to express our appreciation to Drs. I. Abols and N. however, see Coppen et al., 1974, and Montjoy et al., 1974), Brecha for helpful criticism of the manuscript, A. Bond for excellent schizophrenia (Inanaga et al., 1978), amyotrophic lateral scle- technical assistance, and A. Boesman for typing the manuscript. P. W. rosis (Engel et al., 1983), or spinal trauma (Faden et al., 1981). M. is a National Institute of Neurological and Communicative Disor- In the present study, we have examined the distribution of ders and Stroke postdoctoral fellow. TRH receptors in the rat CNS using a modification of the * To whom correspondence should be addressed at current address: Young and Kuhar (1979) autoradiographic binding technique. Center for Ulcer Research and Education, Veterans Administration Previous in vitro binding studies using rat brain homogenates Center, Building 115, Room 217, Los Angeles, CA 90073. have established that the ligand we have used [3H][3-methyl- 551 552 Mantyh and Hunt Vol. 5, No. 2, Feb. 1985 Figure 1. a and b The Journal of Neuroscience Distribution of TRH Receptors in Rat Brain Figure 1. c and d 554 Mantyh and Hunt Vol. 5, No. 2, Feb. 1985 Figure 1. e and f The Journal of Neuroscience Distribution of TRH Receptors in Rat Brain Figure 1. g and h Mantyh and Hunt Vol. 5, No. 2, Feb. 1985 The Journal of Neuroscience Distribution of TRH Receptors in Rat Brain 557 His’lthyrotropin-releasing hormone ( [3H]MeTRH) displays a formed as previously described (Palacios et al., 1981; Hunt and Mantyh, similar pharmacological structure-activity profile as TRH itself 1984). The exposed film was placed onto the stage of a Leitz Orthoplan (Taylor and Burt, 1981b; Simasko and Horita, 1982). Thus, we microscope equipped with a Vario-Orthomat camera system which have used this radiolabeled analogue to visualize the location incorporates a back-projected exposure guide. A small and variable sized spot of light indicates the area of tissue or negative from which of TRH receptors in the CNS. exposure is being read. Direct reading of the voltage content from the photosensitive cell served as a density reading, being directly propor- Materials and Methods tional to the optical density of the film. Previous calibration experi- ments determined at which point given density was increasing in a Male Sprague-Dawley rats (150-250 gm) were killed by decapitation; linear fashion with increasing concentrations of isotope. Nonlinearity the brains rapidly were removed, blocked in the horizontal plane, placed occurs close to saturation of the film and this region was avoided. on brass microtome chucks, and frozen in dry ice. The brains were then serially sectioned (20 pm) and thaw-mounted on gelatin-coated micro- Background labeling was defined as the 5 nM [3H]MeTRH binding that was not displaced in the presence of 10 pM TRH. scope slides and stored at -20°C in boxes of desiccant for 48 hr. Previous brain homogenate studies have extensively defined the optimal incubation conditions necessary to achieve the highest specific/ Results nonspecific binding ratios using [3H]MeTRH as the radioligand (Taylor The results of the autoradiographic studies are shown in Fig. and Burt, 1981b; Simasko and Horita, 1982). In the present study, we 1, a to j and quantified in Table 1. In general, nearly all (95%) have used a nearly identical set of incubation conditions as previously described except that we have performed the incubations on slide- of the TRH receptors were located in the gray matter with very mounted tissue sections rather than brain homogenates. low levels being observed in most white matter tracts (i.e., The slide mounted 20-pm tissue sections were allowed to come to corpus callosum, internal and external capsule). In experiments room temperature and then placed in the incubation medium (0°C on testing for chemography artifacts, no positive or negative chem- ice for 2.5 hr in a cold room 4°C) of 0.1 M sodium phosphate buffer ography was observed in any area of the brain. Experiments to (pH 7.4) containing 5 nM [3H]MeTRH [L-histidyl-4-3H], L-prolyl-3,4- determine the ratio of specific to nonspecific binding showed 3H] (New England Nuclear; specific activity, 76.7 Ci/mmol) in the that the specific binding represented approximately 75% of absence (total binding) or presence (nonspecific binding) of 10 I.IM [3H]MeTRH binding to the slide. TRH. After this incubation period, the slide-mounted tissue sections In presenting the autoradiographic data, we used horizontal were rinsed with three washes of ice-cold 0.1 M sodium phosphate buffer (pH 7.4, 0°C on ice, 5 min each in the cold room at 4°C) and brain sections spaced at approximately 0.5-mm intervals in the three washes of dH,O (0°C on ice, 5 set each in the cold room at 4°C) dorsal-ventral plane so as to provide an atlas of TRH receptors and then quickly dried in the cold room using a stream of cold air. in the rat brain. In describing the distribution of TRH receptors Sections were left a further 3 hr to dry in the cold room and then stored a very low density of receptors will correspond to those areas in desiccant-filled boxes overnight at -20°C. The slides were then having an optical density (OD) of 0.1: low, an OD of 0.2 to 1.0; placed in apposition to LKB tritium-sensitive Ultrofilm.
Load more

Recommended publications
  • The Human Thalamus Is an Integrative Hub for Functional Brain Networks
    5594 • The Journal of Neuroscience, June 7, 2017 • 37(23):5594–5607 Behavioral/Cognitive The Human Thalamus Is an Integrative Hub for Functional Brain Networks X Kai Hwang, Maxwell A. Bertolero, XWilliam B. Liu, and XMark D’Esposito Helen Wills Neuroscience Institute and Department of Psychology, University of California, Berkeley, Berkeley, California 94720 The thalamus is globally connected with distributed cortical regions, yet the functional significance of this extensive thalamocortical connectivityremainslargelyunknown.Byperforminggraph-theoreticanalysesonthalamocorticalfunctionalconnectivitydatacollected from human participants, we found that most thalamic subdivisions display network properties that are capable of integrating multi- modal information across diverse cortical functional networks. From a meta-analysis of a large dataset of functional brain-imaging experiments, we further found that the thalamus is involved in multiple cognitive functions. Finally, we found that focal thalamic lesions in humans have widespread distal effects, disrupting the modular organization of cortical functional networks. This converging evidence suggests that the human thalamus is a critical hub region that could integrate diverse information being processed throughout the cerebral cortex as well as maintain the modular structure of cortical functional networks. Key words: brain networks; diaschisis; functional connectivity; graph theory; thalamus Significance Statement The thalamus is traditionally viewed as a passive relay station of information from sensory organs or subcortical structures to the cortex. However, the thalamus has extensive connections with the entire cerebral cortex, which can also serve to integrate infor- mation processing between cortical regions. In this study, we demonstrate that multiple thalamic subdivisions display network properties that are capable of integrating information across multiple functional brain networks. Moreover, the thalamus is engaged by tasks requiring multiple cognitive functions.
    [Show full text]
  • Higher-Order Thalamic Relays Burst More Than First-Order Relays
    Higher-order thalamic relays burst more than first-order relays E. J. Ramcharan*, J. W. Gnadt†, and S. M. Sherman‡§ *Center for Complex Systems and Brain Sciences, Florida Atlantic University, 777 Glades Road, Boca Raton, FL 33431; †Department of Neurobiology, State University of New York, Stony Brook, NY 11794-5230; and ‡Department of Neurobiology, Pharmacology, and Physiology, University of Chicago, MC 0926, 316 Abbott, 947 East 58th Street, Chicago, IL 60637 Edited by Robert H. Wurtz, National Institutes of Health, Bethesda, MD, and approved July 11, 2005 (received for review April 6, 2005) There is a strong correlation between the behavior of an animal trasted with the higher-order relays, such as the pulvinar for and the firing mode (burst or tonic) of thalamic relay neurons. vision, the magnocellular (or ‘‘nonlemniscal’’) portion of the Certain differences between first- and higher-order thalamic relays medial geniculate nucleus for hearing, and the posterior medial (which relay peripheral information to the cortex versus informa- nucleus for somesthesis, which are thought to serve as a link in tion from one cortical area to another, respectively) suggest that cortico-thalamo-cortical pathways that continue to process these more bursting might occur in the higher-order relays. Accordingly, information streams. we recorded bursting behavior in single cells from awake, behav- We thought that it would be useful to extend the observations ing rhesus monkeys in first-order (the lateral geniculate nucleus, of bursting to higher-order thalamic relays in the behaving the ventral posterior nucleus, and the ventral portion of the medial monkey for the following reasons.
    [Show full text]
  • MRI Atlas of the Human Deep Brain Jean-Jacques Lemaire
    MRI Atlas of the Human Deep Brain Jean-Jacques Lemaire To cite this version: Jean-Jacques Lemaire. MRI Atlas of the Human Deep Brain. 2019. hal-02116633 HAL Id: hal-02116633 https://hal.uca.fr/hal-02116633 Preprint submitted on 1 May 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Distributed under a Creative Commons Attribution - NonCommercial - NoDerivatives| 4.0 International License MRI ATLAS of the HUMAN DEEP BRAIN Jean-Jacques Lemaire, MD, PhD, neurosurgeon, University Hospital of Clermont-Ferrand, Université Clermont Auvergne, CNRS, SIGMA, France This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-nd/4.0/ or send a letter to Creative Commons, PO Box 1866, Mountain View, CA 94042, USA. Terminologia Foundational Model Terminologia MRI Deep Brain Atlas NeuroNames (ID) neuroanatomica usages, classical and french terminologies of Anatomy (ID) Anatomica 1998 (ID) 2017 http://fipat.library.dal.ca In
    [Show full text]
  • Learning & Memory
    Downloaded from learnmem.cshlp.org on September 27, 2021 - Published by Cold Spring Harbor Laboratory Press Review Unraveling the contributions of the diencephalon to recognition memory: A review John P. Aggleton,1,3 Julie R. Dumont,1 and Elizabeth Clea Warburton2 1School of Psychology, Cardiff University, Cardiff, CF10 3AT, Wales, United Kingdom; 2MRC Centre for Synaptic Plasticity, School of Physiology, University of Bristol, Bristol BS8 1TD, United Kingdom Both clinical investigations and studies with animals reveal nuclei within the diencephalon that are vital for recognition memory (the judgment of prior occurrence). This review seeks to identify these nuclei and to consider why they might be important for recognition memory. Despite the lack of clinical cases with circumscribed pathology within the diencepha- lon and apparent species differences, convergent evidence from a variety of sources implicates a subgroup of medial dien- cephalic nuclei. It is supposed that the key functional interactions of this subgroup of diencephalic nuclei are with the medial temporal lobe, the prefrontal cortex, and with cingulate regions. In addition, some of the clinical evidence most readily supports dual-process models of recognition, which assume two independent cognitive processes (recollective-based and familiarity-based) that combine to direct recognition judgments. From this array of information a “multi-effect multi- nuclei” model is proposed, in which the mammillary bodies and the anterior thalamic nuclei are of preeminent importance for recollective-based recognition. The medial dorsal thalamic nucleus is thought to contribute to familiarity-based recog- nition, but this nucleus, along with various midline and intralaminar thalamic nuclei, is also assumed to have broader, indirect effects upon both recollective-based and familiarity-based recognition.
    [Show full text]
  • Projections of Auditory Cortex to the Medial Geniculate Body of the Cat
    THE JOURNAL OF COMPARATIVE NEUROLOGY 430:27–55 (2001) Projections of Auditory Cortex to the Medial Geniculate Body of the Cat JEFFERY A. WINER,* JAMES J. DIEHL, AND DAVID T. LARUE Division of Neurobiology, Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720-3200 ABSTRACT The corticofugal projection from 12 auditory cortical fields onto the medial geniculate body was investigated in adult cats by using wheat germ agglutinin conjugated to horserad- ish peroxidase or biotinylated dextran amines. The chief goals were to determine the degree of divergence from single cortical fields, the pattern of convergence from several fields onto a single nucleus, the extent of reciprocal relations between corticothalamic and thalamocortical connections, and to contrast and compare the patterns of auditory corticogeniculate projec- tions with corticofugal input to the inferior colliculus. The main findings were that (1) single areas showed a wide range of divergence, projecting to as few as 5, and to as many as 15, thalamic nuclei; (2) most nuclei received projections from approximately five cortical areas, whereas others were the target of as few as three areas; (3) there was global corticothalamic- thalamocortical reciprocity in every experiment, and there were also significant instances of nonreciprocal projections, with the corticothalamic input often more extensive; (4) the corti- cothalamic projection was far stronger and more divergent than the corticocollicular projec- tion from the same areas, suggesting that the thalamus and the inferior colliculus receive differential degrees of corticofugal control; (5) cochleotopically organized areas had fewer corticothalamic projections than fields in which tonotopy was not a primary feature; and (6) all corticothalamic projections were topographic, focal, and clustered, indicating that areas with limited cochleotopic organization still have some internal spatial arrangement.
    [Show full text]
  • Amygdalar Interaction with the Mediodorsal Nucleus of the Thalamus and the Ventromedial Prefrontal Cortex in Stimulus-Reward Associative Learning in the Monkey
    The Journal of Neuroscience, November 1990, fO(11): 3479-3493 Amygdalar Interaction with the Mediodorsal Nucleus of the Thalamus and the Ventromedial Prefrontal Cortex in Stimulus-Reward Associative Learning in the Monkey David Gaffan’ and Elisabeth A. Murray* ‘Department of Experimental Psychology, Oxford University, Oxford OX1 3UD, England, and *Laboratory of Neuropsychology, National Institute of Mental Health, Bethesda, Maryland 20892 Cynomolgus monkeys (Macaca fascicularis) were assessed One kind of associative learning in which the amygdala is of for their ability to associate visual stimuli with food reward. central importance is the associationof a sensorystimulus with They learned a series of new 2-choice visual discriminations the incentive value of food reward. In visual-discrimination between colored patterns displayed on a monitor screen. learning for food reward, the role of the amygdala varies ac- The feedback for correct choice was the delivery of food. In cording to the associative structure of the task. If visual dis- order to promote associative learning between the visual criminative stimuli are associateddirectly with the incentive stimuli and the incentive value of the food reward, reward value of the food reward, efficient learning dependson an in- delivery was not accompanied by any distinctive visual feed- trahemispheric interaction between the amygdala and the vi- back on the display screen. The rate of learning new prob- sual-associationcortex ipsilateral to it (E. A. Gaffan et al., 1988). lems was assessed before and after surgery in a total of 16 But when visual discriminative stimuli are associatedwith the monkeys. Three groups of 3 monkeys received bilaterally incentive value indirectly, via the mediation of a direct asso- symmetrical ablations in either the amygdala, the medio- ciation with an auditory or visual secondary reinforcer, visual dorsal nucleus of the thalamus, or the ventromedial pre- interaction with the amygdala is less important (Gaffan and frontal cortex.
    [Show full text]
  • Fmri Assessment of the Pulvinar and Medial Dorsal Nucleus in Normal Volunteers Monte S
    Neuroscience Letters 404 (2006) 282–287 Thalamocortical circuits: fMRI assessment of the pulvinar and medial dorsal nucleus in normal volunteers Monte S. Buchsbaum a,∗, Bradley R. Buchsbaum b, Sylvie Chokron c,d, Cheuk Tang a,e, Tse-Chung Wei a, William Byne a,f a Department of Psychiatry, Mount Sinai School of Medicine, Box 1505, New York, NY 10029-6574, USA b Unit on Integrative Neuroimaging, Clinical Brain Disorders Branch, NIMH, NIH, Bethesda, MD, USA c Laboratoire de Psychologie Experimentale, CNRS, UMR 5105, Grenoble, France d Service de Neurologie, Fondation Ophtalmologique Rothschild, Paris, France e Department of Radiology, Mount Sinai School of Medicine, New York, NY, USA f Bronx VA Medical Center, Bronx, NY, USA Received 27 September 2005; received in revised form 10 March 2006; accepted 15 May 2006 Abstract This fMRI study investigates the activation of the thalamic nuclei in a spatial focusing-of-attention task previously shown to activate the pulvinar with FDG-PET and assesses the connectivity of the thalamic nuclei with cortical areas. Normal right-handed subjects (eight men, eight women, average age = 32 years) viewed four types of stimuli positioned to the right or left of the central fixation point (left hemifield-large letter, left hemifield-small letter display with flanking letters; right hemifield-large letter, right hemifield-small letter display with flankers). BOLD responses to small letters surrounded by flankers were compared with responses to large isolated letters. To examine maximum functional regional connectivity, we modeled “subject” as a random effect and attained fixed effect parameter estimates and t-statistics for functional connectivity between each of the thalamic nuclei (pulvinar, medial dorsal, and anterior) as the seed region and each non-seed voxel.
    [Show full text]
  • Medial Geniculate Lesions Block Amygdalar and Cingulothalamic Learning-Related Neuronal Activity
    The Journal of Neuroscience, November 1, 1997, 17(21):8645–8655 Medial Geniculate Lesions Block Amygdalar and Cingulothalamic Learning-Related Neuronal Activity Amy Poremba1 and Michael Gabriel2 1Department of Psychology and Institute for Neuroscience, Univsity of Texas, Austin, Texas 78712, and 2Department of Psychology and Beckman Institute, University of Illinois, Urbana, Illinois 61801 This study assessed the role of the thalamic medial geniculate anterior-ventral and medial-dorsal thalamic nuclei, and the ba- (MG) nucleus in discriminative avoidance learning, wherein rab- solateral nucleus of the amygdala before training. Learning was bits acquire a locomotory response to a tone [conditioned severely impaired and TIA was abolished in all areas in rabbits stimulus (CS)1] to avoid a foot shock, and they learn to ignore with lesions. Thus learning and TIA require the integrity of the a different tone (CS2) not predictive of foot shock. Limbic MG nucleus. Only damage in the medial MG division was (anterior and medial dorsal) thalamic, cingulate cortical, or significantly correlated with the learning deficit. The lesions amygdalar lesions severely impair acquisition, and neurons in abolished the sensory response of amygdalar neurons, and these areas develop training-induced activity (TIA): more firing they attenuated (but did not eliminate) the sensory response of to the CS1 than to the CS2. MG neurons exhibit TIA during cingulothalamic neurons, suggesting the existence of extra learning and project to the amygdala. The MG neurons may geniculate
    [Show full text]
  • Download English-US Transcript (PDF)
    MITOCW | MIT9_14S14_lec29.mp3 The following content is provided under a Creative Commons license. Your support will help MIT OpenCourseWare continue to offer high-quality educational resources for free. To make a donation or view additional materials from hundreds of MIT courses, visit MIT OpenCourseWare at ocw.mit.edu. PROFESSOR: OK, instead of a quiz I'm trying to write some homework. And some of them will be extra credit, some of them will be part of the required homework. Now today we still have a lot to do on chapter 26 concerning core pathways of the limbic system. And this is where we finished last time. We may not even get to the part on hormones and brain development and effects on the brain, but we may just do most of that with the reading because I really need the time to talk to you about the recent changes in understanding of the hippocampus and the pathways related to it. OK, we answered this question with the information about the internal environment in the body reaches the hypothalamus via both the bloodstream and sensory pathways. And then I asked this about, well, how do these molecules even get in the brain? We know that there's a blood-brain barrier. Very small molecules can get in, but not the larger, organic molecules. And yet, things like angiotensin II do get in, but they get in only at certain places. Places where the blood-brain barrier is weak. I think the figure in the book is a little better than this one, but this is a similar one.
    [Show full text]
  • A Time-Dependent Role of Midline Thalamic Nuclei in the Retrieval of Fear Memory
    Neuropharmacology 62 (2012) 457e463 Contents lists available at SciVerse ScienceDirect Neuropharmacology journal homepage: www.elsevier.com/locate/neuropharm A time-dependent role of midline thalamic nuclei in the retrieval of fear memory Nancy Padilla-Coreano1, Fabricio H. Do-Monte1, Gregory J. Quirk* Departments of Psychiatry and Anatomy & Neurobiology, University of Puerto Rico School of Medicine, P.O. Box 365067, San Juan 00936, Puerto Rico article info abstract Article history: Increasing evidence indicates that the medial prefrontal cortex (mPFC) and the amygdala mediate Received 6 June 2011 expression and extinction of conditioned fear, but few studies have examined the inputs to these Received in revised form structures. The dorsal part of the midline thalamus (dMT) contains structures such as the mediodorsal 21 August 2011 nucleus, paraventricular nucleus, and paratenial nucleus that project prominently to mPFC, as well as to Accepted 22 August 2011 basal (BA) and central (Ce) nuclei of the amygdala. Using temporary inactivation with GABA agonist muscimol, we found that dMT was necessary for retrieving auditory fear memory that was 24 h old, but Keywords: not 2e8 h old. However, pre-training infusions did not impair fear acquisition or extinction. To determine Thalamus Central amygdala the possible targets of dMT that might modulate fear retrieval, we combined dMT inactivation with Fos Fos immunohistochemistry. Rats with inactivation-induced impairment in fear retrieval showed increased Prefrontal cortex Fos in the lateral division of Ce (CeL), and decreased Fos in the medial division of Ce. No differences in Fos Extinction expression were observed in the mPFC or BA. We suggest that the projections from the paraventricular nucleus to CeL are involved in retrieval of well consolidated fear memories.
    [Show full text]
  • Expressing Retinal Ganglion Cells Revealed by Intraocular Injections of Cre-Dependent Virus
    RESEARCH ARTICLE Retinofugal Projections from Melanopsin- Expressing Retinal Ganglion Cells Revealed by Intraocular Injections of Cre-Dependent Virus Anton Delwig1, DeLaine D. Larsen1, Douglas Yasumura1, Cindy F. Yang2, Nirao M. Shah2, David R. Copenhagen1,3* 1 Department of Ophthalmology, UCSF, San Francisco, California, United States of America, 2 Department of Anatomy, UCSF, San Francisco, California, United States of America, 3 Department of Physiology, UCSF, San Francisco, California, United States of America * [email protected] Abstract To understand visual functions mediated by intrinsically photosensitive melanopsin- OPEN ACCESS expressing retinal ganglion cells (mRGCs), it is important to elucidate axonal projections Citation: Delwig A, Larsen DD, Yasumura D, Yang from these cells into the brain. Initial studies reported that melanopsin is expressed only in CF, Shah NM, Copenhagen DR (2016) Retinofugal retinal ganglion cells within the eye. However, recent studies in Opn4-Cre mice revealed Projections from Melanopsin-Expressing Retinal Ganglion Cells Revealed by Intraocular Injections of Cre-mediated marker expression in multiple brain areas. These discoveries complicate the Cre-Dependent Virus. PLoS ONE 11(2): e0149501. use of melanopsin-driven genetic labeling techniques to identify retinofugal projections spe- doi:10.1371/journal.pone.0149501 cifically from mRGCs. To restrict labeling to mRGCs, we developed a recombinant adeno- Editor: Tudor C Badea, NIH/NEI, UNITED STATES associated virus (AAV) carrying a Cre-dependent reporter (human placental alkaline phos- Received: July 27, 2015 phatase) that was injected into the vitreous of Opn4-Cre mouse eyes. The labeling observed in the brain of these mice was necessarily restricted specifically to retinofugal pro- Accepted: February 2, 2016 jections from mRGCs in the injected eye.
    [Show full text]
  • Immunohistochemical Characterization of a Novel Population of Reticular Thalamic Neurons Expressing Cholecystokinin and Type 1 Cannabinoid Receptors
    University of New Hampshire University of New Hampshire Scholars' Repository Master's Theses and Capstones Student Scholarship Winter 2020 IMMUNOHISTOCHEMICAL CHARACTERIZATION OF A NOVEL POPULATION OF RETICULAR THALAMIC NEURONS EXPRESSING CHOLECYSTOKININ AND TYPE 1 CANNABINOID RECEPTORS Shayna Mallat University of New Hampshire, Durham Follow this and additional works at: https://scholars.unh.edu/thesis Recommended Citation Mallat, Shayna, "IMMUNOHISTOCHEMICAL CHARACTERIZATION OF A NOVEL POPULATION OF RETICULAR THALAMIC NEURONS EXPRESSING CHOLECYSTOKININ AND TYPE 1 CANNABINOID RECEPTORS" (2020). Master's Theses and Capstones. 1430. https://scholars.unh.edu/thesis/1430 This Thesis is brought to you for free and open access by the Student Scholarship at University of New Hampshire Scholars' Repository. It has been accepted for inclusion in Master's Theses and Capstones by an authorized administrator of University of New Hampshire Scholars' Repository. For more information, please contact [email protected]. IMMUNOHISTOCHEMICAL CHARACTERIZATION OF A NOVEL POPULATION OF RETICULAR THALAMIC NEURONS EXPRESSING CHOLECYSTOKININ AND TYPE 1 CANNABINOID RECEPTORS BY SHAYNA LYN MALLAT Bachelor of Science in Neuroscience and Behavior, The University of New Hampshire, 2017 THESIS Submitted to the University of New Hampshire in Partial Fulfillment of the Requirements for the Degree of Master of Science in Biological Sciences: Integrative and Organismal Biology December, 2020 i This thesis has been examined and approved in partial fulfillment of the requirements for the degree of Master of Science in Integrative and Organismal Biology by: Thesis Director, Dr. Arturo S. Andrade, Assistant Professor of Neurobiology Dr. Xuanmao Chen, Assistant Professor of Neurobiology Dr. Robert Mair, Professor of Psychology On December 1, 2020 Original approval signatures are on file with the University of New Hampshire Graduate School.
    [Show full text]