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6 mice affects Barnes maze performance
1998 NBTS ABSTRACTS
striatal NGF content, which may be responsible for the delayed expression of the cholinergic phenotype. Hence, use of u-opioid agonists or partial agonists should be approached with care in pregnant women, as changes in NGF content may perturb the development of cholinergic neurons, and may contribute to the behavioral changes observed in the offspring of opioid-exposed mothers. [DA09399]
NBTS30 INMAN, S.L., L.L. MORFORD, M.T. WILLIAMS* and C.V. VORHEES, Div. of Dev. BioI., Children's Hosp. Res. Foundation & Univ. of Cincinnati, Cincinnati, Ohio. Prenatal cocaine treatment in C57BLl6 mice affects Barnes maze performance. The purpose of this study was to compare prenatally cocaine treated (20, 17.5 mg/kg) C57BLl6 mice with controls for spatial learning and memory in the Barnes maze. The Barnes maze is a white disc 122 ern in diameter with 40 5-cm holes, evenly spaced around the perimeter. The animal must learn and remember the relationship among distal cues to navigate to an escape tunnel located beneath one of the holes. Each session begins after 10 sec. when a start chamber is lifted and the number of errors and latency to the first hole and the goal are recorded. Mice receive 2 trials/day (limit 4 min.) to a criterion of 7/8 trials with 3 or fewer errors to a limit of 22 days. Conceptually, the Barnes maze is similar to the Morris maze, but it has been reported to have several advantages. The Barnes maze is physically less taxing, is easily transversed by both young and old animals, and most importantly reveals strategies used during acquisition of the task. Preliminary analysis revealed a main effect of sex (p = 0.0226). Further analysis by sex revealed females prenatally treated with 20 mg/kg required significantly more days to reach criterion performance in the Barnes maze compared to controls (p = 0.0166). No differences on this measure were seen among males. (Supported by NIH grants ES07051 and DA06733)
NBTS 31 BRUNZELL, D.H., BAUER*, A., SPEAR*, R.S., AYRES*, J.J.B, and MEYER, J.S. Neuroscience and Behavior Program, University of Massachusetts,
359
Amherst, MA. Use of a multiple-measure..contexr c.onditionin~paradigmJQ.olltimize...rle.te.ction..nLeffe.cts-Of
prenatal cocaine exposure on.learning, A multiple-trial, multiple-measure contextual fear conditioning paradigm was devised to examine the influence of prenatal cocaine exposure on learning. Sprague-Dawley dams (n=28) received SC injections of either 20 mg/kg cocaine (COC) or saline (SAL) b.i.d, from gestational day (GD) 8 through GD 20. SAL animals were pair-fed to weight-matched cocaine dams. Untreated controls (UT) had ad lib access to food and received no injections. Two male and two female offspring (PD 77-103, n=112) from each litter participated in the study. Same-sex littermates were assigned to either the footshock (S; I shock per session) or no-shock condition (NS). All animals were conditioned in the same chamber once-daily for 4 consecutive days of training. Fecal boli were counted following each session. Pre-shock and post-shock freezing were scored to establish a learning curve of fear conditioning over days. During 3 days of no-shock extinction, access was provided to an adjacent chamber. Fecal boli, and freezing were recorded as before, but the shuttle test enabled observation of nose crossings, side crossings, latency to leave the conditioning chamber, and time spent in each chamber as additional measures of fear. Preliminary results from a subset of the animals revealed a greater latency for S-COC than for S-UT subjects across the 3 extinction days. There was also a main effect of condition (S vs. NS) for defecation, side crossing, latency, and chamber-time. Freezing and nosecrossing data will be presented at the meeting. Supported by NIDA F31 DA-05759 and ROI DA-06495.
NBTS 32 KELLEY, B.M., and L.D. Middaugh, Center for Drug and Alcohol Programs, Medical University of South Carolina, Charleston, South Carolina. Effects of prenatal cocaine on the motor activating and depressing effects, the consumption of, and preference for ethanol in male and female mice. Pregnant C57BLl6J mice were injected daily with cocaine (10 or 20 mg/kg) or saline during gestation days 12-18. Groups did not differ with respect to maternal weight gain nor did offspring differ with respect to birth weight, viability, or growth. Behavioral testing began when the mice were around 80 days old. Exp I: After acclimating to the testing apparatus, daily activity tests (30 min) were conducted on male and female mice injected IP with saline and 0.5, 1.0, 1.5, 2.0, and 2.5 g/kg ethanol, which was followed by 5 daily injections of 3.0
striatal NGF content, which may be responsible for the delayed expression of the cholinergic phenotype. Hence, use of u-opioid agonists or partial agonists should be approached with care in pregnant women, as changes in NGF content may perturb the development of cholinergic neurons, and may contribute to the behavioral changes observed in the offspring of opioid-exposed mothers. [DA09399]
NBTS30 INMAN, S.L., L.L. MORFORD, M.T. WILLIAMS* and C.V. VORHEES, Div. of Dev. BioI., Children's Hosp. Res. Foundation & Univ. of Cincinnati, Cincinnati, Ohio. Prenatal cocaine treatment in C57BLl6 mice affects Barnes maze performance. The purpose of this study was to compare prenatally cocaine treated (20, 17.5 mg/kg) C57BLl6 mice with controls for spatial learning and memory in the Barnes maze. The Barnes maze is a white disc 122 ern in diameter with 40 5-cm holes, evenly spaced around the perimeter. The animal must learn and remember the relationship among distal cues to navigate to an escape tunnel located beneath one of the holes. Each session begins after 10 sec. when a start chamber is lifted and the number of errors and latency to the first hole and the goal are recorded. Mice receive 2 trials/day (limit 4 min.) to a criterion of 7/8 trials with 3 or fewer errors to a limit of 22 days. Conceptually, the Barnes maze is similar to the Morris maze, but it has been reported to have several advantages. The Barnes maze is physically less taxing, is easily transversed by both young and old animals, and most importantly reveals strategies used during acquisition of the task. Preliminary analysis revealed a main effect of sex (p = 0.0226). Further analysis by sex revealed females prenatally treated with 20 mg/kg required significantly more days to reach criterion performance in the Barnes maze compared to controls (p = 0.0166). No differences on this measure were seen among males. (Supported by NIH grants ES07051 and DA06733)
NBTS 31 BRUNZELL, D.H., BAUER*, A., SPEAR*, R.S., AYRES*, J.J.B, and MEYER, J.S. Neuroscience and Behavior Program, University of Massachusetts,
359
Amherst, MA. Use of a multiple-measure..contexr c.onditionin~paradigmJQ.olltimize...rle.te.ction..nLeffe.cts-Of
prenatal cocaine exposure on.learning, A multiple-trial, multiple-measure contextual fear conditioning paradigm was devised to examine the influence of prenatal cocaine exposure on learning. Sprague-Dawley dams (n=28) received SC injections of either 20 mg/kg cocaine (COC) or saline (SAL) b.i.d, from gestational day (GD) 8 through GD 20. SAL animals were pair-fed to weight-matched cocaine dams. Untreated controls (UT) had ad lib access to food and received no injections. Two male and two female offspring (PD 77-103, n=112) from each litter participated in the study. Same-sex littermates were assigned to either the footshock (S; I shock per session) or no-shock condition (NS). All animals were conditioned in the same chamber once-daily for 4 consecutive days of training. Fecal boli were counted following each session. Pre-shock and post-shock freezing were scored to establish a learning curve of fear conditioning over days. During 3 days of no-shock extinction, access was provided to an adjacent chamber. Fecal boli, and freezing were recorded as before, but the shuttle test enabled observation of nose crossings, side crossings, latency to leave the conditioning chamber, and time spent in each chamber as additional measures of fear. Preliminary results from a subset of the animals revealed a greater latency for S-COC than for S-UT subjects across the 3 extinction days. There was also a main effect of condition (S vs. NS) for defecation, side crossing, latency, and chamber-time. Freezing and nosecrossing data will be presented at the meeting. Supported by NIDA F31 DA-05759 and ROI DA-06495.
NBTS 32 KELLEY, B.M., and L.D. Middaugh, Center for Drug and Alcohol Programs, Medical University of South Carolina, Charleston, South Carolina. Effects of prenatal cocaine on the motor activating and depressing effects, the consumption of, and preference for ethanol in male and female mice. Pregnant C57BLl6J mice were injected daily with cocaine (10 or 20 mg/kg) or saline during gestation days 12-18. Groups did not differ with respect to maternal weight gain nor did offspring differ with respect to birth weight, viability, or growth. Behavioral testing began when the mice were around 80 days old. Exp I: After acclimating to the testing apparatus, daily activity tests (30 min) were conducted on male and female mice injected IP with saline and 0.5, 1.0, 1.5, 2.0, and 2.5 g/kg ethanol, which was followed by 5 daily injections of 3.0