|
Summary of Research Projects (Supports in 2004
Fiscal Year)
| Subjects |
Does antennal movement represent insectfs motivation?
A neurobiological study of antennal sensorimotor system in the cockroach |
| Representative researcher |
Department of Biology,Kyushu University
Jiro OKADA |
| The antenna of an insect functions
as a multi-modal sensor for detecting chemical and physical
stimuli, and it is actively movable to scan the surroundings.
To explore the relationship between the animalfs internal
state (motivation or attention) and the antennal movement,
behavioral responses to an attractive or aversive odor were
examined in the searching cockroach. There were at least two
basic states of the antennal movements describing the patterned
and random trajectories. Spectral analyses revealed that the
spatial regularity in antennal trajectories was increased with
the attractive odor stimulus (sex pheromone). Hemocoelic injection
of a muscarinic agonist pilocarpine induced spatially-patterned
movements of the antennae in intact animals. In isolated brain
specimens, pilocarpine also elicited coordinated activities
of the antennal motor nerves. The patterned trajectory may
reflect an activity of the central pattern generator (CPG)
for the antenna, which is frequent in the animals motivated
by the attractive stimulus. The random trajectory seems to
originate from the same CPG, but probably modulated by unknown
sensory inputs. This is more frequent in the searching animals
insensible to useful environmental cues. It would be possible
that the spatial regularity of the antennal movement is a key
index for the animalfs internal state. |
|
Japanese 
returns
to the list