Sensory deprivation during development decreases the responsiveness of cricket giant interneurones.

1. The effect sensory deprivation, early in development, has on the adult response properties of identified neurones was studied in the abdominal nervous system of the cricket Acheta domesticus.2. Neural activity in the cercal-to-giant interneurone system was lowered by blocking the movement of the mechanosensitive hairs, located on each cercus, with a facial cleansing cream.3. When specimens were treated unilaterally one of a pair of homologous neurones exhibited drastically altered response properties. The neurone which received its afferent input from the treated receptors was much less sensitive to tones. Its threshold was increased approximately 20 db with respect to its untreated homologue.4. Bilateral treatment lowered the responsiveness of both of the bilaterally homologous neurones.5. Increased levels of inhibition impinging on the treated neurones accounts for part of the altered responsiveness. The inhibitory pathway is activated by the untreated mechanoreceptors.6. Control experiments demonstrate that the sensory apparatus is not injured or modified by the treatment.7. The results suggest that normal development of some invertebrate neural pathways may be more dependent on experience during ontogeny than has previously been assumed.