ACTION POTENTIAL The localized reversal and then restoration of electrical potential between the inside and the outside of a neuron or muscle cell
AMPHIDS In nematodes, the chemosensory organs that are located laterally in pairs, in the anterior of the body.
CALCIUM TRANSIENT A brief change in fluorescence intensity induced by calcium entering the cell through a voltage-gated calcium channel.
CHOLINERGIC NEURON A neuron that uses acetylcholine as its neurotransmitter.
CONTEXT CONDITIONING Some aspect in the environment (the context) becomes associated with a stimulus and influences later behaviour. (For example, worms habituated to the presence of a distinctive odour showed greater retention of habituation in the presence of the odour than in the absence of the odour.)
DAUER LARVA An example of facultative diapause. In conditions of low food availability and crowding, C. elegans larval development can follow an alternative pathway and form a third-stage larva that is specialized for dispersal and long-term survival. The presence of sufficient food ends diapause and normal development resumes.
DELAYED RECTIFIER A channel that opens when a membrane is depolarized; the membrane repolarizes after an action potential.
DENDRITIC PROCESS A branched, tree-like process that is attached to the cell body of a neuron and that receives input from the axons of other neurons.
DISHABITUATION The rapid facilitation of a behavioural response (often by a new or noxious stimulus) that has been habituated back towards the initial response levels.
GATED Ion channels, such as potassium or calcium channels, can be opened by either a neurotransmitter (for example, glutamate gated or cyclic-nucleotide gated) or by changes in the electrical potential of the neuron (that is, voltage gated).
GRINDER Muscle cells in the terminal bulb of the pharynx secrete thick, ridged cuticles that work together to grind up bacteria and pass it to the intestine.
HABITUATION A decrease in response as a result of repeated stimulation that cannot be explained by sensory adaptation or fatigue.
HYPERPOLARIZATION Refers to any change of the membrane potential to a value that is more negative than the resting potential.
IDENTIFIED NEURON A recognizable neuron that occurs in the same location and has the same function in every member of a species.
INHIBITORY POTENTIAL A hyperpolarization that results from inhibitory synaptic input.
INTERNEURON A neuron that connects with and transmits information only to local neurons.
MECHANOSENSORY NEURON A sensory neuron that is specialized to detect mechanical stimulation (that is, touch or vibration).
NERVE RING In Caenorhabditis elegans, many of the neurons in the nervous system surround the pharynx. Processes from these neurons form an external ring around the pharynx.
NOSE-TOUCH RESPONSE When forward-moving worms bump into an object with their nose, they reverse their direction of movement and back away.
OSMOTIC AVOIDANCE Movement away from high concentrations of sugars and salts.
PATCH CLAMP A technique for recording changes in electrical potentials of individual neurons. It is used as a way of recording neuronal activity.
PHARYNGEAL PUMPING The action of the pharyngeal muscles, which draws food through the pharynx of the worm.
PLASTICITY The ability of a behaviour to change as a result of activity or experience.
RNA INTERFERENCE (RNAi). A process by which double-stranded RNA silences specifically the expression of homologous genes through degradation of their cognate mRNA.
SENSITIZATION An alteration of a baseline-level behavioural response (often by a noxious or arousing stimulus) to levels that are significantly above baseline.
