Behavioral CRs elicited by a lithium- or an amphetamine-paired contextual test chamber

Abstract

The behavioral CRs elicited by a drug-paired contextual cue in rats were measured in a series of experiments. The first three experiments measured the pattern of CRs elicited by a lithiumand an amphetamine-paired CS chamber. The final experiment measured the pattern of URs elicited by lithium or amphetamine when administered in the same chamber. The suppression of grooming-related activities (body washing, face washing, and/or scratching) appeared as a nonspecific effect of both drug USs that was capable of becoming conditioned to the contextual chamber cue. A number of other behaviors differed among conditions, which provides evidence that contextual cue-drug associations are drug-specific. Of the behaviors that differed between the two US drug conditions, lithium CRs showed evidence of behavioral activation (enhanced rearing and limb flicking), but amphetamine CRs showed evidence of behavioral suppression (line crossing, rearing, and shaking). The UR patterns shared some similar and some dissimilar elements of the CR patterns elicited by the CS chamber for both lithium and amphetamine; in fact, by the activity and rearing measures, the URs and CRs were opposite in direction. The results exclusively supported neither stimulus substitution nor conditioned compensatory response accounts of Pavlovian conditioning; instead, each process appears to have accounted for different components of the overall CR pattern.

The effects of acute corticosterone on lithium chloride-induced conditioned place aversion and locomotor activity in rats

“…This finding is inconsistent with previous research showing that LiCl administration causes a suppression of both horizontal and vertical activity (e.g. Johnson, 1975;Smith, 1981;Parker et al, 1984;Tenk et al, 2005). Specifically, the dose of LiCl used in the current study, 64 mg/kg, has been shown to produce significant decreases in the number of gridline crossings, rearing frequency, and time to reach the wall of an open-field (Smith, 1983).…”

“…This delay between injections was intended to overlap the peak of behavioural effects of the two drugs during the conditioning trial. LiCl exerts maximum effects on behaviour 15-30 min following drug administration (e.g., Parker et al, 1984) while acute CORT has effects within 7-15 min following injection (e.g., Sandi et al, 1996a). The first injection was either 64 mg/kg LiCl or NaCl (10 ml/kg) and the second was either 5.0 mg/kg CORT or vehicle; depending on group assignment.…”

Effects of contextual cues previously paired with footshock or illness on behavior and pain sensitivity in the rat

“…Finally, the results of the present experiments add to the growing body of evidence showing that exposure to a distinctive context followed by an injection of LiCl establishes a context-LiCl association in rats. Previously this association has been revealed by reexposing rats to the distinctive context and observing their behavior (e.g., Meachum & Bernstein, 1992;Parker et al, 1984) or by studying the ability of this learning to block subsequent flavor-illness learning in that context (e.g., Best, Brown, & Sowell, 1984;Krane, 1980;Rudy, Iwens, & Best, 1977;Symonds & Hall, 1997;Westbrook & Brookes, 1988;Willner, 1978). The present experiments show that this learning also reliably alters pain sensitivity in rats.…”

“…By contrast, exposure to a context previously paired with an injection of LiCl provokes a suppression of grooming and exploratory behaviors as well as the emergence of freezing (e.g., Meachum & Bernstein, 1992;Parker, Hills, & Jensen, 1984). It is unknown whether this exposure also regulates pain sensitivity in rats.…”

Impaired Conditioned Taste Aversion Learning in Spinophilin Knockout Mice

“…Two observers scored behavior for 20 min and recorded latency to the LOB response. LOB was characterized by periods of immobility, lack of grooming, and a flattened, stretched out posture (Parker et al 1984;Meachum and Bernstein 1990). Mice not observed in the LOB position at any time during the testing period received a latency score of 20 min.…”