Event:

Modification of behavior and its neural control: targeted leg searching movements in the stick insect
Walking stick insects that do not find a foothold perform stereotypic cyclic searching movements
with the respective leg (Bässler, 1993; Dürr, 2001). When encountering an object, the animals grasp
it. I am interested in the control of searching movements that are continued after a one‐time leg
contact with an object that is removed immediately after contact. I could show that upon such a
contact, animals modify certain parameters of their searching movements and target the position of
the previously touched object. This targeted reaction wanes over a time of several seconds and
original searching movements are restored. As the targeted response outlasts the single stimulus by
several seconds, it can be considered to involve a short term memory.
Currently, I explore the neuronal mechanisms underlying searching movements and the targeted
response by intracellularly recording leg moto‐ and premotor interneurons. It appears that
particularly local nonspiking‐interneurons (NSIs) can control searching movements. For example,
single individual interneurons, when depolarized, initiate coordinated searching movements. Other
NSIs, when de‐ or hyperpolarized, change the amplitude of searching movements of one or both leg
joints. Generally, this preparation provides the possibility to explore the neural changes underlying
the modification of (rhythmic) behavior in an in vivo situation.
References:
Bässler (1993), Biol. Cybern. 69, 305‐317
Dürr (2001), JEB 204, 1589‐1604