PT 505 Nuerons and Synapses Part 2

electrical

What type of communication occurs WITHIN neurons?

chemical

What type of communication occurs BETWEEN neurons?

all over

Where are leak channels found on neurons?

potassium

Leak channels establish membrane potential because they always leak:

soma, dendrites

Where are ligand gated ion channels found?

axon

Where are voltage gated ion channels found

synapse

Local connections btw a neuron and a target cells

presynaptic neuron

Releases a neurotransmitter

postsynaptic cell

responds to a neurotransmitter

neurons, muscles, glands

Examples of postsynaptic cells

True

Synapses can occur at different sites. True or False?

Axodendritic

Most common synapse type based on location

distal

Axodendritic synapses are excitatory proximal or distal?

Inhibitory

are axodendritic synapses typical excitatory or inhibitory?

Axosomatic

Fairly common and typically inhibitory synapse type based on location

axoaxonic

Less common synapse type based on location that is typically inhibitory

dendrodendritic

Less common synapse type based on location that can be excitatory or inhibitory

eletrical, chemical

Two main functional categories of synapses

electrical synapses

synapse type used to synchronize membrane potentials and the activity of many neurons, encouraging the neurons to act as a single unit

gap junctions

In electrical synapses, two neurons share cytoplasm via:

chemical

Which is more common: electrical or chemical synapses

chemical synapses

Synapses with presynaptic, synaptic cleft, and postsynaptic sites

presynaptic site

Site of chemical synapses with synaptic vesicles containing neurotransmitters

electrical to chemical

Information transition in the presynaptic site of chemical synapses

synaptic cleft

~20 nm gap where neurotransmitter diffuse from pre to post synaptic site

postsynaptic site

Neurotransmitter receptor in chemical synapses

chemical to electrical

Information transition in the postsynaptic site of chemical synapses

ACh

chemical messenger group that is released at neuromuscular junction and selected site in the brain to move muscles

amino acids

chemical messenger group that includes the most common neurotransmitters of the brain

Glutamate

Amino acid that is used to excite neurons

GABA, glycine

Amino acid that is used to inhibit neurons

Monoamines

chemical messenger group that produces slower, but longer lives excitation OR inhibition

serotonin, dopamine, epinephrine, norepinephrine

What are the monoamine neurotransmitters to remember from class?

presynaptic sites, Ca2+

Step #1 in synaptic transmission occurs at __________________ _____________ and involved APs opening up ________ channels

exocytosis, neurotransmitter

Step #2 in synaptic transmission involves calcium triggering _______________ of synaptic vesicles and __________________ release

synaptic cleft

Step #3 in synaptic transmission involves neurotransmitters crossing where?

receptors

In step #4 in synaptic transmission , _________ create postsynaptic potentials in the postsynaptic neuron

postsynaptic potential summation

What happens in step #5 of synaptic transmission?

reuptake

Synaptic termination mechanism where neurotransmitters are removed by transporter proteins

glutamate, GABA, glycine

What are the "bread and butter" neurotransmitters that undergo reuptake to be recycles

enzymatic degradation

process by which structure of neurotransmitter is altered so it can no longer act on a receptor

monoamines

What neurotransmitters undergo enzymatic degradation

Ca2+

In cholinergic synapses, APs open what kind of channels?

cholinergic synapses

synapses that release ACh

Ca2+

In GABAergic synapses, APs open what kind of channels?

GABA

The Ca2+ channels in GABAergic synapses causes vesicle fusion to release what?

Adrenergic

Synapse that uses G protein couples receptors rather than ion channels

slow, long-lived

describe the effects of adrenergic synapses

Neurotransmitter

Act locally at the site of release

Neuromodulators

Diffuse away from the site of release a bit to act at multiple sites

Neurohormones

Diffuse far away from the site via the bloodstream to act throughout the body

True

Molecules must either act as a neuro -transmitter, -hormone, or -modulator without overlapping. True or False?

perceptions, behaviors

Neurons connected by synapses create circuits that produce:

change synapse strength

How do we change our memories and behaviors?

frequency coding, recruitment

Quantitative neural coding mechanisms

qualitiative

Neural coding mechanism where cells have specific receptors that project to specific area

seeing colors, sweet taste

Examples of qualitative neural coding senses

Diverging

Neural circuit where one neuron controls many (from an upper neuron to lower neuron) to create complex behaviors

converging

Neural circuit where multiple neurons control fewer neurons

reverberating

Neural circuit where excitatory feedback maintains circuit activity

converging

Respiratory centers integrating input from lungs, carotid bodies, and central chemoreceptors is what kind of neural circuit?

Reverberating

What kind of neural circuit would sustained inhalation involve?

parallel after-discharge

Neural circuit where diverging circuits of variable numbers converge to create prolonged input

parallel after-discharge

Withdrawal reflex involves what kind of neural circuit?

serial processing

Processing where linear and neural circuits process information sequentially, as in identifying color

parallel processing

Processing where multiple linear neural circuits process different types of information simultaneously, as in processing visual and auditory information

Perceptions

______________ depend on which patterns of neurons are active

visual

Perceptions that require activity in the occipital lobe

Auditory

Perceptions that require activity in the temporal lobe

strength

The likelihood that a particular pattern of neurons will be active depends on the _____________ of synapses

synaptic plasticity

the ability of a synapse to change over time through use or disuse

hebbian plasticity

neurons that fire together wire together

Long-term potentiation

Increase in synapse strength due to correlated neuronal activity, which is likely the base of memory

long-term depression

decrease in synapse strength due to decorrelated neuronal activity, which is likely the basis of forgetting

working, short-term, long-term

What are the memory types used for facts?

Motor

What is the memory type used to actually do things?

Working

Reverberating circuits and intrinsic excitability is the mechanism occurring in the frontal lobe for what memory?

short-term

LTP and LTD are the mechanisms occuring in the hippocampus for what memory?

Long-term

LTP, LTD, and formations of new synapses are the mechanisms occurring in the cortex for what memory?

Motor

LTP, LTD, and formations of new synapses are the mechanisms occurring in the basal ganglia and cerebellum for what memory?