Puberal status and sex differences: Activity and maze behavior in rats

Contrary t o the statement made in our recent article (Krasnoff & Weston, 1976), the scoring system did differ from that described by Davenport, Hagquist, and Rankin (1970). Errors made in the zones labeled "2" by Davenport et al. were given an error score of "2" rather than "1." The different scoring system in our study as compared with that used by Davenport et al. and by Dawson, Cheung, and Lau (1973) could have influenced the magnitude of the gender differences in maze performance. Clearly, our scoring system inflates errors in relation t o the previous scoring method. sex-based cognitive abilities in the white rat. Psychologia,[16][17][18][19][20][21][22][23][24] behavior in rats. Dev. Psychobiol., 9: 261-269.

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contrasting

confidence: 96%

Erratum

Krasnoff

Weston

1976

Developmental Psychobiology

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“…These sex differences must emerge before, during or after puberty since males and females condition at similar rates prior to puberty (Ivkovich et al, 2000). Others have found similar effects for spatial learning (Kanit et al, 2000;Krasnoff and Weston, 1976). Together, these data suggest that sex differences in learning arise as the capacity for reproduction is being established.…”

Section: Introductionmentioning

confidence: 71%

Distinctive stress effects on learning during puberty

Hodes

Shors

2005

Hormones and Behavior

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Puberty is a time of significant change in preparation for adulthood. Here, we examined how stressful experience affects cognitive and related hormonal responses in male and female rats prior to, during and after puberty. Groups were exposed to an acute stressor of brief periodic tailshocks and tested 24 h later in an associative memory task of trace eyeblink conditioning. Exposure to the stressor did not alter conditioning in males or females prior to puberty but enhanced conditioning in both males and females during puberty. The enhancement occurred in pubescent females irrespective of the estrous cycle. In adulthood, sex differences in trace conditioning and the response to stress emerged: females outperformed males under unstressed conditions, but after stressor exposure, trace conditioning in females was impaired whereas that in males was enhanced. These differences were not related to changes in gross motor activity or other nonspecific measures of performance. The effects of acute stress on corticosterone, estradiol, progesterone, and testosterone were also measured. Stressor exposure increased the concentration of corticosterone in all age groups, although sex differences were only evident in adults. All reproductive hormones except estradiol increased with age in a predictable and sex dependent fashion and none were affected by stressor exposure. Estradiol decreased in male rats across age, and remained stable for female rats. Together, these data indicate that males and female respond similarly to learning opportunities and stressful experience before and during puberty; it is in adulthood that sex differences and the opposite responses to stress arise.

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“…By contrast, the volume of the CA1sr region increased slightly but significantly with age from the prepubertal to the pubertal stage. Thus, overall dendritic spine density decreased throughout the pubertal process, a phenomenon that may underlie pubertal-associated changes in learning and memory (Krasnoff & Weston, 1976).…”

Section: Discussionmentioning

confidence: 99%

“…For example, the hippocampal-dependent task of place navigation, assayed by the Morris water maze, shows a developmental improvement from postnatal days 21 through 64, encompassing the pubertal period (Schenk, 1985). In a different maze task, post-pubertal female rats make more errors than prepubertal rats (Krasnoff & Weston, 1976). This literature is suggestive of changes in hippocampal morphology and ultrastructure during the same developmental period when the ability to learn and remember undergoes changes.…”

Section: Hippocampal Plasticity and Pubertymentioning

confidence: 99%

Postpubertal decrease in hippocampal dendritic spines of female rats

Yıldırım

Mapp

Janssen

et al. 2008

Experimental Neurology

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Hippocampal dendritic spine and synapse numbers in female rats vary across the estrous cycle and following experimental manipulation of hormone levels in adulthood. Based on behavioral studies demonstrating that learning patterns are altered following puberty, we hypothesized that dendritic spine number in rat hippocampal CA1 region would change post-pubertally. Female SpragueDawley rats were divided into prepubertal (postnatal day (P) 22), peripubertal (P35) and postpubertal (P49) groups, with the progression of puberty evaluated by vaginal opening, and estrous cyclicity subsequently assessed by daily vaginal smears. Spinophilin immunoreactivity in dendritic spines was used as an index of spinogenesis in area CA1 stratum radiatum (CA1sr) of hippocampus. First, electron microscopy analyses confirmed the presence of spinophilin specifically in dendritic spines of CA1sr, supporting spinophilin as a reliable marker of hippocampal spines in young female rats. Second, stereologic analysis was performed to assess the total number of spinophilin-immunoreactive puncta (i.e. spines) and CA1sr volume in developing rats. Our results indicated that the number of spinophilin-immunoreactive spines in CA1sr was decreased 46% in the post-pubertal group compared to the two younger groups, whereas the volume of the hippocampus underwent an overall increase during this same developmental time frame. Third, to determine a potential role of estradiol in this process, an additional group of rats was ovariectomized (OVX) prepubertally at P22, then treated with estradiol or vehicle at P35, and spinophilin quantified as above in rats perfused on P49. No difference in spinophilin puncta number was found in OVX rats between the two hormone groups, suggesting that this developmental decrease is independent of peripheral estradiol. These changes in spine density coincident with puberty may be related to altered hippocampal plasticity and synaptic consolidation at this phase of maturity.

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Puberal status and sex differences: Activity and maze behavior in rats

Cited by 53 publications

References 6 publications

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Distinctive stress effects on learning during puberty

Postpubertal decrease in hippocampal dendritic spines of female rats

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