neuro - synapses + ion channels

Stimulus Transduction

Process where stimuli are collected at the boundary membrane and transduced into organismal messages, with membrane fluidity playing a crucial role.

Allostery

Mechanism where biological macromolecules transmit binding effects from one site to another, causing conformational changes for stimulus transduction.

G Protein-Coupled Receptors (GPCRs)

Receptors with seven transmembrane domains, involving activation by ligand binding and subsequent G-protein signaling pathways.

Effectors and Second Messengers

Molecules like adenylyl cyclase and phospholipase C-β generate second messengers such as cAMP, IP3, and DAG, crucial in cellular signaling.

Transient Receptor Potential (TRP) Channels

Channels involved in sensing mechanical and thermal stimuli, permitting ion flow and depolarization of the membrane.

Sensory Adaptation

Includes rapidly and slowly adapting responses, where the frequency of impulses reflects the intensity of the stimulus.

Neurotransmitters

Chemical messengers like ACh, glutamate, GABA, and glycine that play roles in excitatory and inhibitory signaling in the nervous system.

Lateral Line System

Sensory system found in aquatic organisms like fish and amphibians, detecting vibrations, pressure waves, and electroreception in water.

Efferent Control

Mechanism in the lateral line system where signals are sent to inhibit hair cells, preventing overstimulation and interference from the animal's own movements.

Electroreception

Ability of animals to sense weak bioelectric fields passively or actively generate electric fields for environmental perception, as seen in dogfish for passive detection.

Ampullae of Lorenzini

Clusters of canals opening at the body surface in elasmobranchs, forming the ampullary system for detecting electrical cues.

Electrically conductive jelly

Substance that helps conduct electrical signals along the ampullae in elasmobranchs.

Gating inhibition

Mechanism in the nervous system where inhibitory neurons block pain signals from reaching the brain, controlled by releasing enkephalin to hyperpolarize projection neurons.

Decussation

Contralateral movement of sensory information in the spinal cord, where signals from one side of the body are processed by the opposite side of the brain.

Substance P

Neuropeptide released by small sensory axons in response to painful stimuli, exciting projection neurons and contributing to pain perception.

Mechanoreception

Sensory perception carried by large myelinated neurons, influencing pain perception through inhibitory neurons in the dorsal horn of the spinal cord.

Elasmobranch sensory epithelium (SE)

Layer of receptor cells and support cells with tight junctions, forming a barrier to prevent electrical charge leakage in the ampullae system of elasmobranchs.

Buccal and mandibular nerves

Nerves responsible for carrying sensory electroreceptor information from the ampullae of Lorenzini to the brain in elasmobranchs.