The Synapse and Neural Processing

Vocabulary flashcards covering key terms related to synapse function, neurotransmitters, and neural circuits.

Synapse

A junction that mediates information transfer from one neuron to another neuron or to an effector cell.

Presynaptic Neuron

Neuron that conducts impulses toward the synapse.

Postsynaptic Neuron

Neuron that transmits impulses away from the synapse.

Chemical Synapse

Specialized for the release and reception of neurotransmitters and composed of the axon terminal of the presynaptic neuron and the receptor region on the postsynaptic neuron.

Synaptic Cleft

Fluid-filled space separating the presynaptic and postsynaptic neurons, preventing direct nerve impulse transmission.

Neurotransmitter

Chemical released at the synapse to transmit signals from one neuron to another.

EPSP

Excitatory postsynaptic potential; a graded potential that helps trigger an action potential if it reaches threshold strength.

IPSP

Inhibitory postsynaptic potential; a graded potential that reduces the postsynaptic neuron’s ability to produce an action potential.

Acetylcholine (ACh)

Neurotransmitter released at neuromuscular junctions and some ANS neurons; degraded by acetylcholinesterase (AChE).

Biogenic Amines

Neurotransmitters including catecholamines (dopamine, norepinephrine, epinephrine) and indolamines (serotonin, histamine) that play roles in emotional behaviors and the biological clock.

Channel-Linked Receptors

Ligand-gated ion channels that cause immediate and brief actions, mediating excitatory or inhibitory effects via ion fluxes.

G Protein-Linked Receptors

Metabotropic receptors that trigger indirect, slow, complex, and prolonged responses via second messengers.

Neural Pools

Functional groups of neurons that integrate incoming information and forward processed information to other destinations.

Diverging Circuit

One incoming fiber stimulates an ever-increasing number of fibers, often amplifying circuits for sensory and motor systems.

Converging Circuit

Opposite of diverging circuits; results in either strong stimulation or inhibition and is common in sensory and motor systems.

Reverberating Circuit

Chain of neurons containing collateral synapses with previous neurons in the chain.

Parallel After-Discharge Circuit

Incoming fiber stimulates several neurons in parallel arrays to stimulate a common output cell.

Serial Processing

Input travels along one pathway to a specific destination, working in an all-or-none manner to produce a specific response (e.g., reflexes).

Parallel Processing

Input travels along several pathways, promoting numerous responses and is important for higher-level mental functioning.

Growth Cone

Tip of axon that interacts with its environment via cell surface adhesion proteins and neurotropins to guide axonal growth.