
@article {909,
	title = {The dynamic impact of repeated stress on the hippocampal spatial map.},
	journal = {Hippocampus},
	volume = {25},
	year = {2015},
	month = {2015 Jan},
	pages = {38-50},
	abstract = {<p>Stress alters the function of many physiological processes throughout the body, including in the brain. A neural circuit particularly vulnerable to the effects of stress is the hippocampus, a key component of the episodic and spatial memory system in both humans and rodents. Earlier studies have provided snapshots of morphological, molecular, physiological and behavioral changes in the hippocampus following either acute or repeated stress. However, the cumulative impact of repeated stress on in vivo hippocampal physiology remains unexplored. Here we report the stress-induced modulation of the spatially receptive fields of the hippocampal CA1 {\textquoteright}place cells{\textquoteright} as mice explore familiar and novel tracks after 5 and 10 days of immobilization stress. We find that similar to what has been observed following acute stress, five days of repeated stress results in decreased excitability of CA1 pyramidal cells. Following ten days of chronic stress, however, this decreased hippocampal excitability is no longer evident, suggesting adaptation may have occurred. In addition to these changes in neuronal excitability, we find deficient context discrimination, wherein both short-term and chronic stress impair the ability of the hippocampus to unambiguously distinguish novel and familiar environments. These results suggest that a loss of network flexibility may underlie some of the behavioral deficits accompanying chronic stress.</p>
},
	keywords = {Animals, Behavior, Animal, CA1 Region, Hippocampal, Discrimination (Psychology), Generalization (Psychology), Male, Mice, Mice, Inbred C57BL, Spatial Memory, Stress, Psychological, Time Factors},
	issn = {1098-1063},
	doi = {10.1002/hipo.22348},
	author = {Tomar, Anupratap and Polygalov, Denis and Chattarji, Sumantra and McHugh, Thomas J}
}
@article {1016,
	title = {Neighborhood matters: divergent patterns of stress-induced plasticity across the brain.},
	journal = {Nat Neurosci},
	volume = {18},
	year = {2015},
	month = {2015 Oct},
	pages = {1364-75},
	abstract = {<p>The fact that exposure to severe stress leads to the development of psychiatric disorders serves as the basic rationale for animal models of stress disorders. Clinical and neuroimaging studies have shown that three brain areas involved in learning and memory--the hippocampus, amygdala and prefrontal cortex--undergo distinct structural and functional changes in individuals with stress disorders. These findings from patient studies pose several challenges for animal models of stress disorders. For instance, why does stress impair cognitive function, yet enhance fear and anxiety? Can the same stressful experience elicit contrasting patterns of plasticity in the hippocampus, amygdala and prefrontal cortex? How does even a brief exposure to traumatic stress lead to long-lasting behavioral abnormalities? Thus, animal models of stress disorders must not only capture the unique spatio-temporal features of structural and functional alterations in these brain areas, but must also provide insights into the underlying neuronal plasticity mechanisms. This Review will address some of these key questions by describing findings from animal models on how stress-induced plasticity varies across different brain regions and thereby gives rise to the debilitating emotional and cognitive symptoms of stress-related psychiatric disorders.</p>
},
	keywords = {Animals, Brain, Humans, Neuronal Plasticity, Stress, Psychological},
	issn = {1546-1726},
	doi = {10.1038/nn.4115},
	author = {Chattarji, Sumantra and Tomar, Anupratap and Suvrathan, Aparna and Ghosh, Supriya and Rahman, Mohammed Mostafizur}
}
