Phenotypic and genetic relations between initial response to electric shock and rate of avoidance learning in mice

Abstract

The first experiment was designed to determine what proportion of the between-strain variation in rate of avoidance learning could be attributed to strain differences in sensitivity and response topography to electric shock. Measures of jumping at six shock intensities for four inbred strains were collected in a pretest of shock sensitivity. They were then used to derive a shock intensity for each strain which yielded the same amount of jumping for all strains. Avoidance training was administered to other mice of the same age and strains using the same apparatus and shock source as in the pretest. When training was given with a 180 pa shock, significant strain differences were observed in latency of the first escape and total errors to a learning criterion during both jump-out and one-way avoidance training. A large strain by training procedure interaction was found, as well. When training was administered with shock levels which yielded equal jumping in the pretest, strain differences in latency of the first escape were totally eliminated. However, the magnitude of strain differences in the rate of avoidance learning was not changed substantially. A second experiment examined two F 1 hybrid strains and a four-way cross of the inbred strains tested in the first experiment. Results indicated that initial response to shock is characterized by intermediate inheritance, while rate of avoidance learning exhibits significant dominant inheritance. Although significant genetic differences in both initial response to shock and rate of avoidance learning were detected in the present experiments, it is concluded that the former cannot account for the latter.

Genetic Mapping of Vocalization to a Series of Increasing Acute Footshocks Using B6.A Consomic and B6.D2 Congenic Mouse Strains

“…Analysis of consomic strains demonstrated that insertion of A Chr 1 on a B6 background produced an A phenotype and the F1 analysis revealed this phenotype was of intermediate dominance. The pattern of inheritance is in agreement with those of Wahlsten (1972).…”

“…Previous research has indicated that initial sensitivity to footshock has a genetic component, that is an intermediate mode of inheritance (Wahlsten 1972) and early studies suggested that sensitivity to footshock may be modulated by a single gene (Whitney 1969(Whitney , 1973. Analysis of consomic strains demonstrated that insertion of A Chr 1 on a B6 background produced an A phenotype and the F1 analysis revealed this phenotype was of intermediate dominance.…”

“…For example, an intermediate mode of inheritance for sensitivity to footshock stress has been suggested, implying that several genes influence the response (Wahlsten 1972).…”

Go-no go avoidance discriminations in rats with simple “go” and compound “no go” signals: Stimulus modality and stimulus intensity

“…Finally, additional interactions can be expected between stimulus factors and response factors at the instrumental level, since it is well known that response requirements must be evaluated in connection with species-specific defensive behaviors (Bolles. 1971: Wahlsten, 1972.…”

Genetic experiments with animal learning: A critical review

“…It can be shown that the expression for estimating ω 2 given by Hays (1963, p. 382) reduces to for a one-way design with equal numbers of subjects per cell. It should be noted that only two reports Wahlsten, 1971) actually presented values for ω 2 . The remainder were derived by the present author.…”