Biomedical subjects

N M Katovic

Publications and source records attributed to N M Katovic.

3 recordsLinked to original sources

PubMed1999

Schedule-induced polydipsia: gender-specific effects and consequences of prenatal cocaine and postnatal handling.

The impact of gestational cocaine in conjunction with postnatal handling on schedule-induced polydipsia (SIP) was examined. Rat offspring were derived from Sprague-Dawley dams injected subcutaneously with 40 mg/kg/3 cc cocaine hydrochloride (C40) on gestational days 8-20, dams injected with vehicle and pair fed 4 (PF4) days to mimic the acute anorexic effects of cocaine administration, and nontreated (NT) control dams. In adulthood, offspring were food deprived and given 13 daily 30-min SIP sessions, with water intake recorded during the scheduled (fixed time 60 s-FT60) food delivery. For 4 days thereafter, animals received saline, 5 or 10 mg/kg of cocaine in counterbalanced order prior to SIP testing. Acquisition and maintenance of SIP, but not cocaine-induced suppression of SIP performance, were observed to be dependent upon prenatal treatment, handling, and gender. Females acquired SIP faster and exhibited notably higher levels of polydipsia than males. Early handling increased levels of established SIP in NT offspring, while enhancing SIP acquisition in both PF4 and C40 offspring. In nonhandled animals, NT offspring exhibited less SIP than PF4 and C40 offspring, differences that were attenuated by early handling. These effects are discussed in relation to previously reported neurohormonal characteristics of these gender and treatment variables.

Analysis of Variance↗

PubMed1998

Longevity of the expression of behavioral sensitization to cocaine in preweanling rats.

The influence of the treatment-to-test interval on the expression of behavioral sensitization to cocaine was assessed following chronic cocaine exposure during the late preweanling period. From postnatal day 14 (P14) to P20, Sprague-Dawley rat pups received a daily intraperitoneal injection of either 30 mg/kg/2 cc cocaine or an equivalent volume of saline that was paired with placement in the treatment/test context for 30 min. Animals were challenged with 15 mg/kg cocaine in this context on the test day following drug-free intervals of 1, 3, 7, 14, or 21 days. Behavioral sensitization was evident following the preweanling cocaine regimen in terms of both matrix crossings and stereotypy. For matrix crossings, there was no evidence that this sensitization decreased across the time intervals examined, and sensitization was evident with stereotypy even at the 21-day injection test interval. The expression of sensitization, however, was partially overshadowed by an overall reduced sensitivity to cocaine seen in testing during the periadolescent period (i.e., at P34 and P41). Thus, behavioral sensitization to cocaine can be expressed for weeks following chronic treatment during the late preweanling period, although the magnitude of behavioral expression may be influenced by age-related neurobehavioral alterations.

Animals↗

PubMedDate not supplied

Cocaine and development: a retrospective perspective.

Neurobehavioral alterations evident in offspring of Sprague-Dawley rat dams exposed to 40 mg/kg/day cocaine subcutaneously from gestational days 8-20 are reviewed. Consequences for offspring are often age dependent: for instance, reliable deficits in classical conditioning are evident during the early postnatal period, whereas cognitive effects are less pervasive in adulthood, although apparent in tasks such as reversal training. Gender of offspring is another variable of importance, particularly when testing animals in adulthood, with adult male offspring being more likely than their female counterparts to exhibit alterations following the prenatal exposure regimen. Characteristics of the test situation likewise influence detection of outcome effects, with effects particularly likely to emerge under stressful testing conditions or other challenges to the organism. Under these circumstances, alterations in responsiveness to stressors also sometimes emerged in offspring of pair-fed (PF) dams (whose food intake was restricted to match that of cocaine-exposed [COC] dams); these findings perhaps should not be surprising given that pair feeding is a stressor and prenatal stress is known to alter later stressor responsiveness. Although several approaches to equate food intake or avoid pair feeding have yielded disappointing findings, one promising approach is to initiate cocaine administration prior to mating followed by exposure throughout gestation. Premating exposure to cocaine was sufficient to eliminate anorexic effects of drug delivery during pregnancy, although it remains to be seen how similar the pattern of neurobehavioral alterations that emerge with this extended exposure regimen will be to effects seen following more restricted gestational exposure.

Animals↗