Behavioral neuroscience “Psychobiology” redirects here. For the journal, see was distrusted by the dominant anatomists of the 18th and Cognitive, Affective, & Behavioral Neuroscience. 19th centuries.[5] The influential work of Claude Bernard, “Biological psychology” redirects here. For the journal, Charles Bell, and William Harvey helped to convince the see Biological Psychology (journal). scientific community that reliable data could be obtained For related topics, see Affective neuroscience, Behavioral from living subjects. neurology, Cognitive neuroscience, Neuropsychiatry, Even before the 18th and 19th century, behavioral neu- Neuropsychology, and Social neuroscience. roscience was beginning to take form as far back as 1700 B.C.[6] The question that seems to continually arise is Behavioral neuroscience, also known as biological psy- what is the connection between the mind and body. The chology,[1] biopsychology, or psychobiology[2] is the debate is formally referred to as the Mind-body problem. application of the principles of biology (in particular There are two major schools of thought that attempt to neurobiology), to the study of physiological, genetic, and resolve the mind–body problem; monism and dualism.[3] developmental mechanisms of behavior in humans and Plato and Aristotle are two of several philosophers who non-human animals. It typically investigates at the level participated in this debate. Plato believed that the brain of neurons, neurotransmitters, brain circuitry and the ba- was where all mental thought and processes happened.[6] sic biological processes that underlie normal and abnor- In contrast, Aristotle believed that the brain served the mal behavior. Often, experiments in behavioral neuro- purpose of cooling down the emotions derived from the science involve non-human animal models (such as rats heart.[3] The Mind-body problem was a stepping stone and mice, and non-human primates) which have impli- toward attempting to understand the connection between cations for better understanding of human pathology and the mind and body. therefore contribute to evidence-based practice. Another debate arose about was localization of function or Functional specialization (brain) versus equipotentiality which played a significant role in the 1 History development in behavioral neuroscience. As a result of localization of function research, many famous people found within psychology have come to various different Behavioral neuroscience as a scientific discipline conclusions. Wilder Penfield was able to develop a map emerged from a variety of scientific and philosophical of the cerebral cortex through studying epileptic patients traditions in the 18th and 19th centuries. In philosophy, along with Rassmussen.[3] Research on localization of people like René Descartes proposed physical models function has led behavioral neuroscientist to a better to explain animal and human behavior. Descartes, for understanding of which parts of the brain control example, suggested that the pineal gland, a midline behavior. This is best exemplified through the case study unpaired structure in the brain of many organisms, was of Phineas Gage. the point of contact between mind and body. Descartes The term “psychobiology” has been used in a variety of also elaborated on a theory in which the pneumatics contexts,emphasizing the importance of biology, which of bodily fluids could explain reflexes and other motor is the discipline that studies organic, neural and cellular behavior. This theory was inspired by moving statues in modifications in behavior, plasticity in neuroscience, and a garden in Paris.[3] biological deceases in all aspects, in addition, biology fo- Other philosophers also helped give birth to psychology. cuses and analyzes behavior and all the subjects it is con- One of the earliest textbooks in the new field, The Princi- cerned about, from a scientific point of view. In this con- ples of Psychology by William James (1890), argues that text, psychology helps as a complementary, but impor- the scientific study of psychology should be grounded in tant discipline in the neurobiological sciences. The role an understanding of biology: of psychology in this questions is that of a social tool that James, like many early psychologists, had considerable backs up the main or strongest biological science. The training in physiology. The emergence of both psychol- term “psychobiology” was first used in its modern sense ogy and behavioral neuroscience as legitimate sciences by Knight Dunlap in his book An Outline of Psychobiol- [7] can be traced from the emergence of physiology from ogy (1914). Dunlap also was the founder and editor-in- anatomy, particularly neuroanatomy. Physiologists con- chief of the journal Psychobiology. In the announcement ducted experiments on living organisms, a practice that of that journal, Dunlap writes that the journal will pub- 1 2 3 RESEARCH METHODS lish research "...bearing on the interconnection of mental • Surgical lesions - Neural tissue is destroyed by and physiological functions”, which describes the field of removing it surgically. [7] behavioral neuroscience even in its modern sense. • Electrolytic lesions - Neural tissue is destroyed through the application of electrical shock trauma. 2 Relationship to other fields of • Chemical lesions - Neural tissue is destroyed psychology and biology by the infusion of a neurotoxin. • Temporary lesions - Neural tissue is tem- In many cases, humans may serve as experimental porarily disabled by cooling or by the use of subjects in behavioral neuroscience experiments; how- anesthetics such as tetrodotoxin. ever, a great deal of the experimental literature in be- havioral neuroscience comes from the study of non- • Transcranial magnetic stimulation - A new tech- human species, most frequently rats, mice, and mon- nique usually used with human subjects in which keys. As a result, a critical assumption in behavioral neu- a magnetic coil applied to the scalp causes unsys- roscience is that organisms share biological and behav- tematic electrical activity in nearby cortical neurons ioral similarities, enough to permit extrapolations across which can be experimentally analyzed as a func- species. This allies behavioral neuroscience closely tional lesion. with comparative psychology, evolutionary psychology, evolutionary biology, and neurobiology. Behavioral neu- • Psychopharmacological manipulations - A chemical roscience also has paradigmatic and methodological sim- receptor antagonist induces neural activity by inter- ilarities to neuropsychology, which relies heavily on the fering with neurotransmission. Antagonists can be study of the behavior of humans with nervous system dys- delivered systemically (such as by intravenous in- function (i.e., a non-experimentally based biological ma- jection) or locally (intracerebrally) during a surgical nipulation). procedure into the ventricles or into specific brain structures. For example, NMDA antagonist AP5 Synonyms for behavioral neuroscience, though with has been shown to inhibit the initiation of long term a slightly different emphasis and organization, in- potentiation of excitatory synaptic transmission (in clude biopsychology, biological psychology, and rodent fear conditioning) which is believed to be a psychobiology.[8] Physiological psychology is another vital mechanism in learning and memory.[9] term often used synonymously with behavioral neuro- science, though most authors would make physiological • Optogenetic inhibition - A light activated inhibitory psychology a subfield of behavioral neuroscience, with protein is expressed in cells of interest. Power- an appropriately more narrow definition. ful millisecond timescale neuronal inhibition is in- stigated upon stimulation by the appropriate fre- quency of light delivered via fiber optics or im- 3 Research methods planted LEDs in the case of vertebrates,[10] or via external illumination for small, sufficiently translu- cent invertebrates.[11] Bacterial Halorhodopsins or The distinguishing characteristic of a behavioral neuro- Proton pumps are the two classes of proteins used science experiment is that either the independent variable for inhibitory optogenetics, achieving inhibition by of the experiment is biological, or some dependent vari- increasing cytoplasmic levels of halides (Cl-) or de- able is biological. In other words, the nervous system of creasing the cytoplasmic concentration of protons, the organism under study is permanently or temporarily respectively.[12][13] altered, or some aspect of the nervous system is measured (usually to be related to a behavioral variable). 3.2 Enhancing Neural Function 3.1 Disabling or decreasing neural func- • Electrical stimulation - A classic method in which tion neural activity is enhanced by application of a small electrical current (too small to cause significant cell • Lesions - A classic method in which a brain-region death). of interest is naturally or intentionally destroyed to observe any resulting changes such as degraded or • Psychopharmacological manipulations - A chemi- enhanced performance on some behavioral measure. cal receptor agonist facilitates neural activity by en- Lesions can be placed with relatively high accuracy hancing or replacing endogenous neurotransmitters. thanks to a variety of brain 'atlases’ which provide Agonists can be delivered systemically (such as by a map of brain regions in 3-dimensional stereotactic intravenous injection) or locally (intracerebrally) coordinates. during a surgical procedure.