Neural Basis of Behavior & Phenotypic Plasticity – Key Vocabulary

Thirty-five vocabulary flashcards summarizing essential terms from the lecture on phenotypic plasticity, neural mechanisms of behavior, stimulus processing, and sensory ecology.

Phenotypic plasticity

The capacity of a single genotype to produce more than one phenotype in response to environmental cues.

Polyphenism

A special case of phenotypic plasticity in which discrete, environmentally triggered alternative phenotypes are produced.

Density-dependent polyphenism

A polyphenism where the phenotype expressed depends on the population density experienced by the organism.

Socially-induced polyphenism

Phenotypic changes triggered by social cues such as the presence or absence of conspecifics; common in many fish species.

Food-induced polyphenism

Environmentally driven shifts in phenotype caused by differences in diet or nutritional quality.

Predator-induced polyphenism

Environmentally cued phenotypic changes (e.g., thicker shells, spines) that occur when predators or predator chemicals (kairomones) are detected.

Kairomone

A chemical signal emitted by one species and detected by another, benefiting the receiver (e.g., predator cue detected by prey).

Behavioral polymorphism

The loss of plastic control over behavioral roles, often resulting in genetically fixed alternative behaviors controlled by supergenes.

Supergene

A chromosomal region containing several tightly linked genes that together influence a complex trait such as behavior.

Neuron

The fundamental cell of the nervous system specialized for sending and receiving electrical and chemical signals.

Dendrite

Branch-like extensions of a neuron that receive incoming signals from other neurons or sensory receptors.

Axon

A long projection of a neuron that conducts electrical impulses away from the cell body toward other neurons or effectors.

Synapse

The junction between neurons where electrical impulses trigger the release of neurotransmitters to propagate a signal.

Neural circuit

An interconnected group of neurons that process specific information and produce coordinated output.

Action potential

A rapid, transient electrical signal that travels along the axon when a neuron’s threshold is exceeded.

Sensory receptor

A specialized cell or neuron that detects external or internal stimuli and converts them into neural signals.

Innate behavior (instinct)

A behavior pattern that is fully formed and functional the first time it is performed, requiring no prior experience.

Releaser (sign stimulus)

A specific external cue that triggers an innate behavioral response.

Fixed action pattern

A stereotyped, innate sequence of behaviors that is completed once initiated by a releaser.

Innate releasing mechanism

The neural circuit that recognizes a releaser and initiates the corresponding fixed action pattern.

Stimulus filtering

The neural process of ignoring irrelevant information while focusing on biologically important stimuli.

Echolocation

The use of emitted sound pulses and analysis of returning echoes to navigate and locate objects, common in bats.

A1 receptor cell

One of the auditory neurons in noctuid moth ears that detects bat ultrasound and encodes distance and direction.

Circadian clock

An internal, roughly 24-hour biological oscillator modulated by environmental cues such as light.

UV light compass

Navigation mechanism in monarch butterflies that relies on ultraviolet light cues to initiate correct migratory direction.

Polarized light navigation

Orientation using the angle of polarized sunlight, enabling monarchs to maintain course even under cloud cover.

Brood parasitism

A reproductive strategy where one species lays eggs in the nest of another, leaving parental care to the host.

Coevolutionary arms race

The reciprocal evolutionary adaptations between interacting species, such as parasites and their hosts.

Sonar jamming

Emission of ultrasonic clicks by prey (e.g., tiger moths) that interfere with a bat’s echolocation.

Tiger moth ultrasonic clicks

High-frequency sounds produced when a bat approaches, hypothesized to startle, warn, or jam bat sonar.

Eimer’s organ

A tactile sensory structure found on the rays of a star-nosed mole’s nose, rich in mechanoreceptors.

Cortical magnification

Disproportionate allocation of brain cortex to body parts or sensory inputs of high behavioral importance.

Mechanoreceptor

A sensory receptor responsive to mechanical pressure or distortion, fundamental to touch and hearing.

Auditory tuning curve

A graph showing the sensitivity of an auditory receptor or neuron across different sound frequencies.

Parasitoid fly (Ormia ochracea)

A fly species whose females locate singing male crickets via specialized auditory receptors to deposit larvae.