Introduction
Living organisms such as human beings have mechanisms to react to various conditions of external environments. These reactions are generally a sequence of movements that combine to produce a smooth and efficient action and are known as motor actions or motor skills.
Motor control refers to the information processing related activities that are carried out by the central nervous system to organize the musculoskeletal system and subsequently create these coordinated movements and skilled actions.
The smallest biological unit that is involved in motor control is called a Motor unit. A motor unit is made up of a motor neuron and the skeletal muscle fibres which innervated by the axon of that motor neuron. These motor units work in group to control the contractions in a single muscle and bring about the required movements.
Motor control mainly concerns two types of actions:
1) Voluntary
2) Reflex
This study focuses mainly on the study of voluntary motor control using Caenorhabditis elegans (C.elegans) as model organism and aims to generate a computational model of the underlying neural circuit.
Previous studies and Motivation
Various studies on Caenorhabditis elegans, which is a free-living, transparent nematode (roundworm), have revealed the Nervous system of the adult C.elegans hermaphrodite in great details.
An adult C.elegans hermaphrodite has 302 neurons that belong to two distinct and independent nervous systems: a large somatic nervous system (282 neurons) and a small pharyngeal nervous system (20 neurons). These systems communicate through a single pair of RIP interneurons. These neurons communicate through approximately 6400 chemical synapses, 900 gap junctions, and 1500 neuromuscular junctions (NMJs). Among individual animals, the location of chemical synapses is about 75% reproducible.
Based on these studies, several models of C.elegans neural circuit have been proposed. Some of them aimed at understanding the processing of stimulation information in the neuronal circuit and tried to determine the flow of information processing in detail. Others tried to integrate the flow series from reception of the stimulation to motion generation in a very simplified form.
One such neuronal circuit model for touch simulation in C.elegans was developed by Michio Suzuki et al. In this model they developed a model for neural connection for light touch and integrated it with a kinematic model of the body and thus constructed a whole body model of C.elegans.
In this project I would like to generate a similar neural circuit model and try to observe the motor actions at neuronal level.
Methodology
A methodology similar to that as described in the model by Suzuki et al will be followed. Data for neural connections in C.elegans can be obtained from Database of synaptic connectivity of C.elegans and the mathematical models based on neural networks can be derived for a single neuron. These individual models can then be integrated to generate the complete model for motor control in C.elegans.