Brain and Behavior Exam 1

corpus callosum

a large bundle of nerve fibers that connects corresponding parts of one side of the brain with those of the other

split-brain operation

brain surgery that is occasionally performed to treat a form of epilepsy; the surgeon cuts the corpus callosum, which connects the two hemispheres of the brain

cerebral hemispheres

the two symmetrical halves of the brain; they constitute the major part of the brain

generalization

type of scientific explanation; a general conclusion based on many observations of similar phenomena

reduction

type of scientific explanation; a phenomenon is described in terms of the more elementary processes that underlie it

reflex

an automatic, stereotyped movement produced as the direct result of a stimulus

model

a mathematical or physical analogy for a physiological process

doctrine of specific nerve energies

Muller’s conclusion that because all nerve fibers carry the same type of message, sensory information must be specified by the particular nerve fibers that are active

experimental ablation

the research method in which the function of a part of the brain is inferred by observing the behaviors an animal can no longer perform after that part is damaged

functionalism

the principle that the best way to understand a biological phenomenon is to try to understand its useful functions for the organism

natural selection

the process by which inherited traits that confer a selective advantage become more prevalent in the population

evolution

a gradual change in the structure and physiology of plant and anima species - generally producing more complex organisms - as a result of natural selection

mutation

a change in the genetic information contained in the chromosomes of sperms or eggs, which can be passed on to an organism’s offspring; provides genetic variability

selective advantage

a characteristic of an organism that permits it to produce more than the average number of offspring of its species

behavioral neuroscientist

a scientist who studies the physiology of behavior, primarily by performing physiological and behavioral experiments with laboratory animals

neuraxis

an imaginary line drawn through the center of the length of the central nervous system, from the bottom of the spinal cord to the front of the forebrain

anterior

located near or toward the head

posterior

located near or toward the tail

rostral

“toward the beak”; in a direction along the neuraxis toward the front of the face

caudal

“toward the tail”; in a direction along the neuraxis away from the front of the face

dorsal

“toward the back”; perpendicular to the neuraxis toward the top of the head or the back

ventral

“toward the belly”; perpendicular to the neuraxis toward the bottom of the skull or the front surface of the body

lateral

toward the side of the body, away from the middle

medial

toward the middle of the body, away from the side

ipsilateral

located on the same side of the body

contralateral

located on the opposite side of the body

central nervous system

brain

spinal cord

peripheral nervous system

nerves

peripheral ganglia

cross section

a slice taken at right angles to the neuraxis

frontal section

a slice through the brain parallel to the forehead

horizontal section

a slice through the brain parallel to the ground

sagittal section

a slice through the brain parallel to the neuraxis and perpendicular to the ground

midsagittal plane

the plane through the neuraxis perpendicular to the ground; divides the brain into two symmetrical halves

meninges

the three layers of tissue that encase the CNS; the dura mater, arachnoid membrane, and pia mater

dura mater

the outermost of the meninges; tough and flexible

arachnoid membrane

the middle layer of the meninges, located between the outer dura mater and inner pia mater

pia mater

the layer of the meninges that clings to the surface of the brain; thin and delicate

subarachnoid space

the fluid-filled space that cushions the brain; located between the arachnoid membrane and the pia mater

cerebrospinal fluid (CSF)

a clear fluid, similar to blood plasma, that fills the ventricular system of the brain and the subarachnoid space surrounding the brain and spinal cord

ventricle

one of the hollow spaces within the brain, filled with cerebrospinal fluid

lateral ventricle

one of the two ventricles located in the center of the telencephalon

third ventricle

the ventricle located in the center of the diencephalon

cerebral aqueduct

a narrow tube interconnecting the third and fourth ventricles of the brain, located in the center of the mesencephalon

fourth ventricle

the ventricle located between the cerebellum and the dorsal pons, in the center of the metencephalon

choroid plexus

the highly vascular tissue that protrudes into the ventricles and produces cerebrospinal fluid

neural tube

a hollow tube, closed at the rostral end, that forms ectodermal tissue early in embryonic development; serves as the origin of the CNS

cerebral cortex

the outermost layer of gray matter of the cerebral hemispheres

progenitor cells

cells of the ventricular zone that divide and give rise to cells of the CNS

ventricular zone (VZ)

a layer of cells that line the inside of the neural tube; contains progenitor cells that divide and give rise to cells of the CNS

symmetrical division

division of a progenitor cell that gives rise to two identical progenitor cells; increases the size of the ventricular zone and hence the brain that develops from it

asymmetrical division

division of a progenitor cell that gives rise to another progenitor cell and a neuron, which migrates away from the VZ toward its final resting place in the brain

radial glia

special glia with fibers that grow radially outward from the VZ to the surface of the cortex; provide guidance for neurons migrating outward during brain development

neurogenesis

the production of new neurons within the brain

forebrain

the most rostral of the three major divisions of the brain; includes the telencephalon and diencephalon

cerebral hemisphere

one of the two major portions of the forebrain, covered by the cerebral cortex

subcortical region

the region located within the brain, beneath the cortical surface

sulcus/sulci

a groove, smaller than a fissure, in the surface of the cerebral hemisphere

fissure

a major groove in the surface of the brain

gyrus/gyri

a convolution of the cortex of the cerebral hemispheres, separated by sulci or fissures

primary visual cortex

the region of the posterior occipital lobe whose primary input is from the visual system

calcarine fissure

a fissure located in the occipital lobe on the medial surface of the brain; most of the primary visual cortex is located along its upper and lower banks

primary auditory cortex

the region of the superior temporal lobe whose primary input is from the auditory system

lateral fissure

the fissure that separates the temporal lobe from the overlying frontal and parietal lobes

primary somatosensory cortex

the region of the anterior parietal lobe whose primary input is from the somatosensory system

central sulcus

the sulcus that separates the frontal lobe from the parietal lobe

primary motor cortex

the region of the posterior frontal lobe that contains neurons that control movements of skeletal muscles

frontal lobe

the anterior portion of the cerebral cortex, rostral to the parietal lobe and dorsal to the temporal lobe

parietal lobe

the region of the cerebral cortex caudal to the frontal lobe and dorsal to the temporal lobe

temporal lobe

the region of the cerebral cortex rostral to the occipital lobe and ventral to the parietal and frontal lobes

occipital lobe

the region of the cerebral cortex caudal to the parietal and temporal lobes

sensory association cortex

those regions of the cerebral cortex that receive information from the regions of primary sensory cortex

motor association cortex

the region of the frontal lobe rostral to the primary motor cortex; aka the premotor cortex

prefrontal cortex

the region of the frontal lobe rostral to the motor association cortex

corpus callosum

a large bundle of axons that interconnects corresponding regions of the association cortex on each side of the brain

neocortex

the phylogenetically newest cortex, including the primary sensory cortex, primary motor cortex, and association cortex

limbic cortex

phylogenetically old cortex, located at the medial edge of the cerebral hemispheres; part of the limbic system

cingulate gyrus

a strip of limbic cortex lying along the lateral walls of the groove separating the cerebral hemispheres, just above the corpus callosum

limbic system

a group of brain regions including the anterior thalamic nuclei, amygdala, hippocampus, limbic cortex, and parts of the hypothalamus, as well as their interconnecting fibers

hippocampus

a forebrain structure of the medial temporal lobe, constituting an important part of the limbic system; involved in learning and memory

amygdala

a structure in the interior of the rostral temporal lobe, containing a set of nuclei; part of the limbic system

fornix

a fiber bundle that connects the hippocampus with other parts of the brain, including the mammillary bodies of the hypothalamus; part of the limbic system

mammillary bodies

a protrusion of the bottom of the brain at the posterior end of the hypothalamus, containing some hypothalamic nuclei; part of the limbic system

basil ganglia

a group of subcortical nuclei in the telencephalon, the caudate nucleus, the globus pallidus, and the putamen; important parts of the motor system

nucleus

an identifiable group of neural cell bodies in the CNS

diencephalon

a region of the forebrain surrounding the third ventricle; includes the thalamus and hypothalamus

thalamus

the largest portion of the diencephalon, located above the hypothalamus; contains nuclei that project information to specific regions of the cerebral cortex and receive info from it

projection fiber

an axon of a neuron in one region of the brain whose terminals form synapses with neurons in another region

lateral geniculate nucleus

a group of cell bodies within the lateral geniculate body of the thalamus that receives fibers from the retina and projects fibers to the primary visual cortex

medial geniculate nucleus

a group of cell bodies within the medial geniculate body of the thalamus; receives fibers from the auditory system and projects fibers to the primary auditory cortex

ventrolateral nucleus

a nucleus of the thalamus that receives inputs from the cerebellum and sends axons to the primary motor cortex

hypothalamus

the group of nuclei of the diencephalon situated beneath the thalamus; involved in regulation of the automatic nervous system, control of the anterior and posterior pituitary glands, and integration of species-typical behaviors

optic chiasm

an X-shaped connection between the optic nerves, located below the base of the brain, just anterior to the pituitary gland

anterior pituitary gland

the anterior part of the pituitary gland; an endocrine gland whose secretions are controlled by the hypothalamic hormones

neurosecretory cell

a neuron that secretes a hormone or hormonelike substance

posterior pituitary gland

the posterior part of the pituitary gland; an endocrine gland that contains hormone-secreting terminal buttons of axons whose cell bodies lie within the hypothalamus

midbrain

the mesencephalon; the central of the three major divisions of the brain

mesencephalon

the midbrain; a region of the brain that surrounds the cerebral aqueduct; includes the tectum and tegmentum

tectum

the dorsal part of the midbrain; includes the superior and inferior colliculi

superior colliculi

protrusions on top of the midbrain; part of the visual system

inferior colliculi

protrusions on top of the midbrain; part of the auditory system