Learning and Memory (Neurosciences)

Mescaline facilitates retention of passive avoidance in rats

by Jeffrey Kahn, M.D.

Jeffrey P Kahn, David A Gorelick, Wagner H Bridger
Physiological Psychology (later Psychobiology) 06/1974; 2(2):120-122.

Tested the hypothesis that hallucinogens produce memory disturbance. Of 81 male hooded rats, half were given 1 trial... more Tested the hypothesis that hallucinogens produce memory disturbance. Of 81 male hooded rats, half were given 1 trial of step-through passive avoidance, then immediately injected with saline or mescaline (160 mmol/kg intraperitoneally) and tested for retention 48 hrs later. Controls were given identical treatments, except that they did not receive footshock during the training trial. Groups receiving footshock showed learning and retention, with the mescaline group showing better retention than the saline group. The no-footshock groups showed no learning, with the mescaline group not differing from the saline. In a separate experiment, rats were given 1 trial of step-through passive avoidance, then injected with saline or mescaline 72 hrs later and tested for retention 48 hrs after injection. The mescaline and saline groups did not differ, indicating that mescaline did not have a 48-hr proactive effect on performance in this task. (PsycINFO Database Record (c) 2010 APA, all rights reserved)

Examining the structure and role of emotion: Contributions of neurobiology to the study of embodied religious experience

by Rebecca Sachs Norris

In Zygon: The Journal of Science and Religion, 40:1, March 2005.

Certain properties of the body and emotions facilitate the transmission of religious knowledge and the development of... more Certain properties of the body and emotions facilitate the transmission of religious knowledge and the development of religious states through particular qualities of perception and memory. The body, which is the ground of religious experience, can be understood as transformative: the characteristic that recalled emotion is “refelt” in the present enables emotion to be cultivated or developed. Emotions and the stimuli that evoke them are necessarily culturally specific, but the automatic nature of this process is universal. Religious traditions have made use of these processes to educate the feeling toward certain qualities and to develop religious experience, through the use of sacred images, ritual posture and gesture, and repetition of ritual acts. Neuroscience contributes to our understanding of the emotional processes that take place when emotions are evoked, refelt, and developed; the neurobiological processing of emotion parallels experience. Keeping experience central makes it possible to bring religion and neuroscience together in a nonreductive examination of spiritual experience.

Light experience and the development of behavioural lateralisation in chicks:II. Choice of familiar versus unfamiliar model social partner

by Andrew Robins

Andrew, R.J., Johnston, A.N.B., Robins, A. and Rogers, L.J. (2004). “Light experience and the development of behavioural lateralisation in chicks. II. Choice of familiar versus unfamiliar model social partners.” Behavioural Brain Research, 155: 67-76.

In late-stage embryos of domestic fowl, exposure of the right eye to light entering through the shell induces... more In late-stage embryos of domestic fowl, exposure of the right eye to light entering through the shell induces asymmetry of the thalamofugal visual pathway, together with differences in performance according to whether the right or left eye (RE, LE) is in use (Behav. Brain Res. 38 (1990) 211). Nevertheless, at least some of the main specialisations of the right and left eye systems (RES, LES) are not dependent on such exposure. Higher ability of LES to assess and respond to novelty is present in dark-incubated (Da) chicks. This is probably also true of RES ability to control response, and specifically to inhibit shift to an alternative response (i.e. to a novel stimulus). We imprinted chicks on red table-tennis balls with a horizontal, white strip on their equator. At test, they chose between this and a ball with a vertical, white strip. Da chicks showed clear choice with the LE, but not with the RE. Unexpectedly, light-incubated (Li) chicks failed to show LE/RE differences in choice. Exploratory pecks at a novel feature were greatly reduced in Li. Two effects of light exposure on RES are likely. The first is greater use of RES in the home-cage, affecting what is learned about the companion ball. This may make RES more competent in assessing ball properties, and so explain the enhanced choice by RE, that abolished the RE/LE difference in Li. Secondly, the ability of RES to inhibit shift to an alternative response is enhanced. Light exposure and being female similarly opposed shift to the novel feature, but probably via different mechanisms. The effects of exposure are discussed as an example of the generation of a range of behavioural phenotypes, which are sustained within a single population by varying or frequency-dependent selection.

Intrahippocampal Norleucine1-Angiotensin IV mitigates scopolamine-induced spatial working memory deficits

by Ian Cero

The Roles of CaMKII and F-Actin in the Structural Plasticity of Dendritic Spines: A Potential Molecular Identity of a Synaptic Tag?

by Miquel Bosch

Physiology (Bethesda). 2009 Dec;24:357-66

Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) and actin are two crucial molecules involved in long-term... more Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) and actin are two crucial molecules involved in long-term potentiation (LTP). In addition to its signaling function, CaMKII plays a structural role via direct interaction with actin filaments, thus coupling functional and structural plasticity in dendritic spines. The status of F-actin, regulated by CaMKII, determines the postsynaptic protein binding capacity and thus may act as a synaptic tag that consolidates LTP.

Ecstasy (MDMA) and Memory Function: a Meta-Analytic Update

by Keith Laws

Laws KR & Kokkalis J (2007)

A meta-analysis was conducted to examine the impact of recreational ecstasy use on short-term memory (STM), long-term... more A meta-analysis was conducted to examine the impact of recreational ecstasy use on short-term memory (STM), long-term memory (LTM), verbal and visual memory.We located 26 studies containing memory data for ecstasy and non-ecstasy users from which effect sizes could be derived. The analyses provided measures of STM and LTMin 610 and 439 ecstasy users and revealed moderate-to-large effect sizes (Cohen’s d) of d=0.63 and d=0.87, respectively. The difference between STM versus LTM was non-significant. The effect size for verbal memory was large (d=1.00) and significantly larger than the small effect size for visual memory (d=0.27). Indeed, our analyses indicate that visual memory may be affected more by concurrent cannabis use. Finally, we found that the total lifetime number of ecstasy tablets consumed did not significantly predict memory performance.