Dept. of Psychology
Center for Collaborative Neuroscience
Rutgers University
Piscataway, NJ

Tel: 732 445-6968
FAX: 732 445-2263

shors@rci.rutgers.edu

Webpage

My major research objective is to understand how memories are formed and maintained in the mammalian brain. This is of course not an easy task since memories are made seemingly instantaneously and some are preserved for the rest of our lives. Therefore, the mechanisms that underlie this amazing feat are very rapidly induced and persistently expressed. Given that so many cells are born each day in the hippocampus, we have proposed that they may be involved in the formation of new memories and have accumulated considerable evidence that they are. First, we found that learning enhances their survival. Second, we have found that the depletion of these cells results in significant deficits in learning abilities. Together, our data suggest that these new neurons are not only affected by new learning but may be involved in the formation of memories themselves.
The second focus of my laboratory concerns sex differences in learning and how males and females are differentially affected by stressful experience. Using associative learning tasks, we have found that males and females can learn at very different rates and that they are affected in opposite ways by exposure to stressful experience. More specifically, we have reported that exposure to an uncontrollable stressful event greatly enhances new learning in male rats but severely impairs new learning in female rats. These effects are dependent on the psychological aspects of stress, namely the absence of control. Their expression depends on both organizational and activational effects of hormones and they are associated with anatomical changes in the brain including changes in the formation of dendritic spines. In general, our data suggest that sex differences in learning processes and in response to stress are mediated by anatomical changes in the brain that are broadly induced by the presence of sex and stress hormones that change as we age and experience significant life events.
Women are much more likely to experience stress-related mental illnesses such as depression, anxiety and post-traumatic stress disorders. Despite these numbers, females are rarely studies in laboratory experiments. One of my major goals over the next several years is to evaluate learning abilities and responses to stressful experience in the female rat across her lifespan. It is my hope that this line of research will lead to important discoveries about the neuronal mechanisms that underlie the formation of memories and how memories, these most essential features of our existence can be preserved and maintained throughout our lifetimes.

For complete list: PubMed

Leuner B., Mendolia S., Kozorovitskiy Y., Samburg D., Gould E., Shors T.J. (2004) Learning enhances the survival of new neurons beyond the time when the hippocampus Is required for memory. J. Neurosci., 24:7477–7481.

Shors T.J. (2004) Memory traces of trace memories: neurogenesis, synaptogenesis and awareness. Trends in Neuroscience, 27, 250-256.

Shors T.J. (2004) Learning during stressful times. Learning and Memory, 11, 137-144.

Shors T.J., Falduto J., Leuner B. (2004) Opposite effects of stress and sex differences in dendritic spines are dependent on NMDA receptor activation. Eur. J. Neurosci. 19, 145-150.

Leuner B., Mendolia S., Shors T.J. (2004) High levels of estrogen enhance associative learning in the female rat. Psychoneuroendocrinology, In press, ..

Leuner B., Shors T.J. (2004) New spines, new memories. Molecular Neurobiology, In press

Bangasser D. and Shors T.J. (2004) Stressful experience impairs the trace conditioning the females without altering the unconditioned response. Neurobiology of Learning and Memory, In press.

Alder J., Thakker-Varia S., Bangasser D.A., Kuroiwa M., Plummer M.R., Shors T.J., Black I.B. (2003) BDNF-induced gene expression reveals novel actions of VGF in hippocampal synaptic plasticity. J. Neurosci., 23, 10800-10808.