Chp 2 Definitions

EPSP (excitatory postsynaptic potential)

graded depolarization

IPSP (inhibitory postsynaptic potential)

temporary hyper polarization of a membrane

postsynaptic neuron

neuron that receives transmission from another

presynaptic neuron

neuron that delivers transmission to another neuron

reflex arc

a circuit from sensory neuron to muscle response

reflexes

automatic muscular responses to stimuli

spatial summation

combination of effects of activity from two or more synapses onto a single neuron

spontaneous firing rate

a periodic production of action potentials even w/out synaptic input

synapse

a specialized gap as a point of communication between two neurons anatomy of chemical events

temporal summation

a cumulative effect of repeated stimuli within a brief time

acetylcholine

chemical similar to an amino acid except it includes N(CH3)3 instead of an NH2 group

amino acids

acids containing an amine group (NH2)

amphetamine

drug that blocks reuptake of dopamine and other neurotransmitters

anterior pituitary

portion of the pituitary gland, composed of glandular tissue

autoreceptors

receptors on a presynaptic neuron that provide negative feedback by responding to the transmitter released by that neuron

cannabinoids

chemicals related to D-9-THC

catecholamines

compounds that contain a catechol and an amine group

cocaine

a drug that blocks repuptake of dopamine

exocytosis

release of neurotransmitter from the presynaptic neuron into the synaptic cleft

G protein

coupled to guanosine triphosphate (GTP) an energy storing molecule

gap junction

direct contact of one neuron with another, enabling electrical transmission

gases

one of the categories of neurotransmitters including nitric oxide and possibly others

hallucinogenic drugs

drugs that distort perception

hormone

chemical that is secreted by cells in one part of the body and conveyed by the blood to influence other cells

ionotrophic effects

synaptic effects that depend on the rapid opening of some kind of gate in the membrane

metabotropic effects

sequence of metabolic reactions that produce slow and longlasting effects at a synapse

methylphenidate

stimulant drug prescribed for ADHD that increases the stimulation of dopamine synapses by blocking the reuptake of dopamine by the presynaptic neuron

monoamines

chemicals formed by change in certain amino acids

neuromodulators

chains of amino acids

neuropeptides

chains of amino acids

neurotransmitters

chemicals released by neurons that affect other neurons

nitric oxide

a gas released by many small local neurons

opiate drugs

drugs derived from the opium poppy

oxytocin

hormone released by posterior pituitary; important for sexual and parental behaviors

pituitary gland

an endocrine gland attached to the base of the hypothalamus

posterior pituitary

portion of the pituitary gland, which releases hormones synthesized by the hypothalamus

purines

a category of chemicals including adenosine and several of its derivatives

reuptake

reabsorption of a neurotransmitter by the presynaptic terminal

secondary messenger

a chemical that when activated by a neurotransmitter initiates communication to many areas within a neuron

synaptic cleft

the space between the presynaptic and postsynaptic neurons

transporter

special membrane protein where reuptake occurs in the neurotransmitter binds to it

vasopreessin

(antidiuretic hormone) hormone released by posterior pituitary raises blood pressure and enables kidneys to conserve water

vesicles

tiny nearly spherical packets filled with neurotransmitter molecules