Exam 2 Review

Electrical Synapses

Direct transmission via gap junctions; faster, bidirectional.

Chemical Synapses

Use neurotransmitters; slower but allow signal modulation; unidirectional.

Synaptic cleft

The small gap between the presynaptic and postsynaptic neurons.

Presynaptic terminal

The end of the neuron that releases neurotransmitters.

Postsynaptic membrane

The surface of the receiving neuron that contains receptors for neurotransmitters.

Neurotransmitter

Chemicals that transmit signals across a synapse from one neuron to another.

Neurotransmitter release

The process in which a neurotransmitter is released into the synaptic cleft.

Action potential

A rapid electrical signal traveling along a neuron.

Voltage-gated Ca²⁺ channels

Channels that open when the action potential arrives, allowing calcium ions to enter.

Ca²⁺ influx

The entry of calcium ions into the presynaptic terminal, triggering neurotransmitter release.

Quantal release

Neurotransmitters are released in discrete packets called quanta.

EPSP (Excitatory Postsynaptic Potential)

A depolarizing potential that increases the likelihood of neuron firing.

IPSP (Inhibitory Postsynaptic Potential)

A hyperpolarizing potential that decreases the likelihood of neuron firing.

Reuptake

The reabsorption of neurotransmitters into the presynaptic neuron.

Synaptic vesicles

Small sacs in the presynaptic terminal that store neurotransmitters.

Diffusion

The movement of neurotransmitters away from the synaptic cleft.

Amino acids neurotransmitters

Fast-acting neurotransmitters like glutamate and GABA.

Peptide neurotransmitters

Slow-acting neurotransmitters that influence long-term neural circuits.

G-Protein Coupled Receptors

Receptors that activate intracellular signaling pathways leading to slower effects.

Second messengers

Molecules that relay signals inside the cell after receptor activation.

Autoreceptors

Receptors that regulate neurotransmitter release via negative feedback.

Transmitter-Gated Ion Channels

Channels that open to allow ion flow when a neurotransmitter binds.

G-Protein Signaling Sequence

Sequence where neurotransmitter binding activates G-proteins and subsequent pathways.

Axodendritic Synapse

A synapse between an axon and a dendrite.

Axosomatic Synapse

A synapse between an axon and a soma (cell body).

Axoaxonic Synapse

A synapse between two axons.

Dendrodendritic Synapse

A synapse between two dendrites.

Quick neurotransmitter degradation

Reuptake, enzymatic breakdown, diffusion.

Acetylcholine (Ach)

An excitatory neurotransmitter involved in muscle contraction.

GABA (Gamma-Aminobutyric Acid)

An inhibitory neurotransmitter that reduces neuronal excitability.

Glutamate

An important excitatory neurotransmitter involved in plasticity and learning.

Fast neurotransmitters

Neurotransmitters such as amino acids that act quickly.

Slow neurotransmitters

Neurotransmitters such as peptides that act over longer periods.

Neuropeptides

Slow-acting neurotransmitters that influence emotional and pain responses.

Patch-Clamp Recording

A technique used to measure ion flow and neurotransmitter release.

Electrophysiology

The study of electrical properties of biological cells and tissues.

Neurotransmitter binding

The process where neurotransmitters attach to receptors on the postsynaptic membrane.

Neurotransmitter classification

Categorization based on function, speed of action, or chemical structure.

Synapse function

Facilitates communication between neurons.

CNS (Central Nervous System)

Brain and spinal cord.

PNS (Peripheral Nervous System)

Cranial/spinal nerves, autonomic system.

Dorsal roots

Sensory pathways carrying information to the CNS.

Ventral roots

Motor pathways carrying commands from the CNS.

CSF circulation

The flow of cerebrospinal fluid through the ventricles.

Brain imaging techniques

Methods to visualize brain structure and function, like MRI and CT.

Hindbrain

The part of the brain that controls basic survival functions.

Forebrain regions

Includes the cortex, thalamus, and hypothalamus, involved in complex functions.

Lobes of the brain

Frontal (motor), Parietal (sensory), Temporal (auditory), Occipital (visual).

Shunting Inhibition

Inhibitory inputs reduce membrane resistance to prevent depolarization.

PSP (Postsynaptic Potential)

A change in the electrical charge of the postsynaptic neuron.

Neurotransmitter criteria

Must be synthesized, released upon stimulation, and evoke a response.

GABA function

Acts as the primary inhibitory neurotransmitter in the brain.

Endorphins

Peptide neurotransmitters involved in pain relief and pleasure.

Dopamine function

Amino acid neurotransmitter involved in reward and motivation.