Multivariate statistical analysis of the response of the cockroach giant interneuron system to wind puffs

Abstract

The cockroach Periplaneta Americana responds to wind puffs by turning from the source of the wind. This turning movement is thought to be initiated by sensory responses to the wind puff occurring on filiform haircells on the cerci. The responses on the haircells initiate responses on 14 giant interneurons that rapidly transfer the information about the puff from the abdomen to the thorax and head. This response, in turn, is thought to initiate the escape response on the cockroach. In this paper a multivariate statistical analysis of the response of the 14 giant interneurons to wind puffs from a variety of angles is considered. A temporal-spatial integration model is proposed for the neural processing units acting as terminators for the giant interneurons and it is shown that using appropriate spatial integration, the cockroach can accurately estimate the direction of a wind puff on the basis of the response seen on the giant interneurons. It is also shown that with appropriate spatial integration, wind puffs from the left can be discriminated from wind puffs from the right. The right-left discrimination method is shown to be robust against the loss of any single giant interneuron. In some cases several giant interneurons can be lost without losing the right-left discrimination ability.