Correlations between temperature effects on behavior in aplysia and firing patterns of identified neurons

Abstract

1) During recovery from short‐term exposure to a temperature which produced cold inactivation, facets of Aplysia's behavioral repertoire reappear in the following sequence: local reflexes reappear first (4–5°C), general withdrawal reflexes involving responses of unstimulated regions reappear next (7–9°Q, and coordinated whole animal responses such as locomotion are recovered upon further warming (9–11 °Q.

2) Intracellular recordings from identified neurons in the abdominal ganglion showed that the cells have characteristic temperature ranges in which they are active (Figure 3).

3) Comparisons of behavioral responses and the thermal sensitivity of central neurons suggest that local withdrawal reflexes can be elicited at a temperature below the thermal cut‐off for central neuronal activity. Recovery of general withdrawal behaviors correlated well with the onset of responsiveness of motoneurons in the gill‐withdrawal pathway. Whole animal behavior could be elicited at temperatures at which the nervous system showed a higher general level of activity and bursting pacemakers had become active.

Notes

Present address: Department of Zoology, Washington State University, Pullman, Washington 99163.