Abstract
Purpose: :
By measuring optomotor response (OMR), we examined whether the motion detection is influenced by GABA and glycine which are known as the typical inhibitory neurotransmitters. OMR is the instinctive behavior of animals which is generated by the continuous visual stimuli. The degree of contribution of color vision in the motion detection, the development of perception of vision, the function of the area of intelligence in the retina & brain, the recognition of motion in the process of aging and the function of the neurotransmitter have been studied by the observation of OMR.
Methods: :
Experimental setup for OMR measurement was similar to ones used by Schaerer and Neumeyer (1996). The apparatus was composed of a luminous source, a fishbowl and the rotating pattern drum. All drugs were dissolved and 2.0 µL was injected into goldfish by intraocular injection.
Results: :
The intraocular injection of GABA decreased OMR, but glycine did not produce any effect. Baclofen and cis-4-aminocrotonic acid (CACA), agonist of GABAB and GABAC receptor respectively, did not decrease OMR. But the intraocular injection of muscimol induced the special behavior as the concentration of the drug was increased. In low concentrations of muscimol, the decrease of the behavior of rotating in the opposite was observed, and the trait of the opposite rotating motion was increased notably according to the increasement of the concentration of the drugs. Bicuculine, an antagonist of GABAA receptor, rather decreased OMR.
Conclusions: :
These results represent that the formation of the signaling of motion detection seems to be modulated in the inner retina and there the extra-activation of GABAA receptors evokes illusory motion reversal through any lateral inhibitory pathway.
Keywords: detection • neurotransmitters/neurotransmitter systems • retina