Clues to basis of exploratory behaviour of theC. eleganssnout from head somatotropy

Abstract

Wave propagation during locomotory movements of is constrained to a single dorso/ventral plane. By contrast, the tip of the head (snout) can make rapid exploratory movements in all directions relative to the body axis. These extra degrees of freedom are probably important for animals to seek and identify desirable passages in the interstices of the three-dimensional matrix of soil particles, their usual habitat. The differences in degrees of freedom of movement between snout and body are reflected in the innervation of the musculature. Along the length of the body, the two quadrants of dorsal muscle receive common innervation as do the two quadrants of ventral muscle. By contrast, muscles in the snout have an octagonal arrangement of innervation. It is likely that the exploratory behaviour of the snout is mediated by octant-specific motor and sensory neurons, together with their associated interneurons. The well-defined anatomical structure and neural circuitry of the snout together with behavioural observations should facilitate the implementation of models of the neural basis of exploratory movements, which could lead to an understanding of the basis of this relatively complex behaviour, a behaviour that has similarities to foraging in some vertebrates.This article is part of a discussion meeting issue 'Connectome to behaviour: modelling at cellular resolution'.

Kinesin-3 mediated axonal delivery of presynaptic neurexin stabilizes dendritic spines and postsynaptic components

“…In this case, GABAergic spines may have developed to intercept cholinergic release sites onto muscles, as suggested previously (J. White, 2018).…”

Statistical analysis of unidirectional and reciprocal chemical connections in the C. elegans connectome

“…Despite the seeming simplicity of RCPs and UCPs, the conditions and mechanisms responsible for their formation and functional role remain an open problem (Emmons, 2016;White, 2018). The number of synapses between neurons F I G U R E 1 Schematic depiction of a reciprocally connected pair (RCP) of neurons i and j with axodendritic synapses.…”

“…Despite the seeming simplicity of RCPs and UCPs, the conditions and mechanisms responsible for their formation and functional role remain an open problem (Emmons, 2016; White, 2018). The number of synapses between neurons (synaptic multiplicity) is known to be plastic, changing throughout development and in different physiological conditions.…”

Connectome to behaviour: modelling Caenorhabditis elegans at cellular resolution

“…Most of the quantitative data on worm behaviour is collected from worms crawling on a smooth agar surface, but in nature they are likely to encounter heterogeneous threedimensional environments. White [22] hypothesizes that the extra degrees of freedom of the worm's snout are important for navigating these more complex environments and looks to the neural circuitry in the head for insights into possible control mechanisms.…”