Drugs and behavior Chapter 4 Flashcards
homeostasis
maintenance of an environment of body functions within a certain range
membrane
a tin, limiting covering of a cell
cell body
the central region of a neuron, which is the control center
dendrites
branchlike structures that extend from the sell body and specialize in receiving signals from other neurins
axon
a thin tube that extends from the cell body and specializes in transmitting signals to other neurons
axon terminals
the end region of the axon
receptors
recognition mechanisms that respond to specific signals
neurotransmitter
chemical messengers released from axon terminals
synaptic vessicles
small bubbles of membrane that store neurotransmitters
mylein
a fatty white substance that is wrapped around potions of the axons
autoimmune disease
a condition that occurs when the immune system mistakenly attacks and destroys healthy body tissue
multiple sclerosis
an autoimmune illness caused by damage to the mylein sheath that wraps axons. A wide range of symptoms can accompany this disorder including muscle spasms, vision loss, severe pain, dizziness, fatigue, and intestinal problems
blood brain barrier
structure that prevents many drugs from entering the brain
semipermable
allowing some, but not all, chemicals to pass
nerotransmission
the process of transferring information from one neuron to another at a synapse
action potential
the electrical signal transmitted along the axon when a neuron fires
ion channels
a protein in the cell membrane forms a pore that allows the passage of ions from one side of the membrane to the other
ion
an atom or molecule that has a net electrical charge because of a difference in the number of electron and protons
resting potential
the voltage maintained by a cell when it is not generating action potentials. The resting potential of neurons is about -65 mV
hyperpolarized
when the membrane potential is more negative
depolarized
when the membrane potential is less negative
acetylcholine
neurotransmitter found in the parasympathetic branch in the cerebral cortex
autonomic
the part of the nervous system that controls “involuntary” functions, such as heart rate
sympathetic
the branch of the autonomic system involved in flight or fight response
parasympathetic
the branch of the autonomic system that stimulates digestion, slows the heart, and has other effects associated with a relaxed physiological state
norepinephrine
neurotransmitter that may be important for regulating waking and appetite
central nervous system
brain and spinal cord
nucleus accumbens
a collection of neurons in the fore bain that plays an important role in reward and emotional reactions to events
dopamine
neurotransmitter found in the basal ganglia and other regions
ventral tegmental area
a group of dopamine containing neurons located in the mid brain whose axons project to the fore brain, especially the nucleus accumbens and cortex
mesolimbic dopamine pathway
one of the 2 major dopamine pathways; may be involved in psychotic reactions and in drug rewards
schizophrenia
a mental disorder characterized by chronic psychosis
nigrostriatal dopamine pathway
one of two major dopamine pathways; damaged in Parkinson’s disease
substantia nigra
a dopamine- rich midbrain structure that projects to the striatum
hypothalamus
a structure found near the bottom of the forebrain. It participates in the regulation of hunger, thirst, sexual behavior, and aggression
striatum
a term used to describe the caduate nucleus and putamen. Located in the forebrain, it is involved in the initiation of body movements and procedural memory
Parkinson’s Diesease
a movement disorder involving damage to and/or loss of dopamine neurons along the nigrostriatal dopmanine pathway. Major symptoms include tremors, rigidity of the limbs, postural instability, and the difficulty initiating movments
precursors
chemicals that are acted on by enzymes to form neurotransmitters
nucleus basalis
a group of neurons of the basal forebrain that sends projections throughout the cortex
cerebral cortex
the outermost layer of the brain
Alzheimer’s disease
a progressive brain disease that destroys memory and thinking skills
serotonin
neurotransmitter found in the raphe nuclei; may be important for important for impulsivity, depression
raphe nuclei
a group of serotonin- containing neurons found in the brain stem and project widley throughout the brain
GABA
inhibitory neurotransmitter found in most regions throughout the brain
glutamate
excitatory neurotransmitter found in most regions of the brain
endorphin
opiate- like chemical that occurs naturally in the brain of humans and other animals
basal ganglia
subcortal brain structures controlling muscle tome
uptake
energy- requiring mechanisms by which selected molecules are taken into cells
synthesis
the forming of a neurotransmitter by the action of enzymes on precusors
enzyme
large molecule that assists in either the synthesis or metabolism of another molecule
synapse
the space between neurons
transporter
mechanism in the nerve terminal membrane responsible for removing neurotransmitter molecules from the synapse by taking them back into the neuron
metabolize
to break down or inactivate a neurotransmitter through enzymatic action
agonist
a substance that facilitates or mimics the effects of a neurotransmitter on the post synaptic cell
antagonist
a substance that prevents the effects of a neurotransmitter on the pos tsynaptic cell
monomaine
a class of chemicals characterized by a single amine group; monoamine neurotransmitters including dopamine, norephrine, and serotonin
