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The role of the hippocampus in avoidance learning and anxiety vulnerability.

Cominski TP, Jiao X, Catuzzi JE, Stewart AL, Pang KC - Front Behav Neurosci (2014)

Bottom Line: In the current study, we examined the effect of hippocampal damage in avoidance learning, as avoidance is a core symptom of all anxiety disorders.The WKY rat is an animal model of behavioral inhibition, a risk factor for anxiety, and demonstrates abnormal avoidance learning, marked by facilitated avoidance acquisition and resistance to extinction.These results suggest that hippocampal dysfunction enhances the development of persistent avoidance responding and, thus, may confer vulnerability to the development of anxiety disorders and PTSD.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology and Neurosciences, Rutgers - New Jersey Medical School, Rutgers, The State University of New Jersey , Newark, NJ , USA.

ABSTRACT
The hippocampus has been implicated in anxiety disorders and post-traumatic stress disorder (PTSD); human studies suggest that a dysfunctional hippocampus may be a vulnerability factor for the development of PTSD. In the current study, we examined the effect of hippocampal damage in avoidance learning, as avoidance is a core symptom of all anxiety disorders. First, the effect of hippocampal damage on avoidance learning was investigated in outbred Sprague Dawley (SD) rats. Second, the function of the hippocampus in Wistar-Kyoto (WKY) rats was compared to SD rats. The WKY rat is an animal model of behavioral inhibition, a risk factor for anxiety, and demonstrates abnormal avoidance learning, marked by facilitated avoidance acquisition and resistance to extinction. The results of the current study indicate that hippocampal damage in SD rats leads to impaired extinction of avoidance learning similar to WKY rats. Furthermore, WKY rats have reduced hippocampal volume and impaired hippocampal synaptic plasticity as compared to SD rats. These results suggest that hippocampal dysfunction enhances the development of persistent avoidance responding and, thus, may confer vulnerability to the development of anxiety disorders and PTSD.

No MeSH data available.


Related in: MedlinePlus

LTP of the dentate gyrus population spike following HFS of the medial perforant pathway in SD and WKY rats. Following HFS, SD rats exhibited robust early and late phase LTP of the population spike (A). In contrast to SD rats, early or late phase LTP of the population spike was not observed in WKY rats (B).
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Figure 7: LTP of the dentate gyrus population spike following HFS of the medial perforant pathway in SD and WKY rats. Following HFS, SD rats exhibited robust early and late phase LTP of the population spike (A). In contrast to SD rats, early or late phase LTP of the population spike was not observed in WKY rats (B).

Mentions: Similar to fEPSP, LTP of the population spike was observed in SD but not in WKY rats (Figures 5 and 7A,B). In SD rats, early and late phase LTP were observed (Figure 7A), as main effect of phase [F(2, 10) = 22.393, p < 0.001] and the phase × stimulus intensity interaction [F(12,60) = 7.014 p < 0.001] were significant. The main effect of stimulus intensity was also significant, [F(6,30) = 14.660, p < 0.001]. LTP of the population spike was not observed in WKY rats (Figure 7B). Neither main effect of phase [F(2,10) = 4.291; corrected p = 0.085] nor the phase × stimulus intensity interaction [F(12,60) = 1.543, p = 0.134] were significant, although the main effect of stimulus intensity was significant, [F(6,30) = 3.081, p = 0.018].


The role of the hippocampus in avoidance learning and anxiety vulnerability.

Cominski TP, Jiao X, Catuzzi JE, Stewart AL, Pang KC - Front Behav Neurosci (2014)

LTP of the dentate gyrus population spike following HFS of the medial perforant pathway in SD and WKY rats. Following HFS, SD rats exhibited robust early and late phase LTP of the population spike (A). In contrast to SD rats, early or late phase LTP of the population spike was not observed in WKY rats (B).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4125878&req=5

Figure 7: LTP of the dentate gyrus population spike following HFS of the medial perforant pathway in SD and WKY rats. Following HFS, SD rats exhibited robust early and late phase LTP of the population spike (A). In contrast to SD rats, early or late phase LTP of the population spike was not observed in WKY rats (B).
Mentions: Similar to fEPSP, LTP of the population spike was observed in SD but not in WKY rats (Figures 5 and 7A,B). In SD rats, early and late phase LTP were observed (Figure 7A), as main effect of phase [F(2, 10) = 22.393, p < 0.001] and the phase × stimulus intensity interaction [F(12,60) = 7.014 p < 0.001] were significant. The main effect of stimulus intensity was also significant, [F(6,30) = 14.660, p < 0.001]. LTP of the population spike was not observed in WKY rats (Figure 7B). Neither main effect of phase [F(2,10) = 4.291; corrected p = 0.085] nor the phase × stimulus intensity interaction [F(12,60) = 1.543, p = 0.134] were significant, although the main effect of stimulus intensity was significant, [F(6,30) = 3.081, p = 0.018].

Bottom Line: In the current study, we examined the effect of hippocampal damage in avoidance learning, as avoidance is a core symptom of all anxiety disorders.The WKY rat is an animal model of behavioral inhibition, a risk factor for anxiety, and demonstrates abnormal avoidance learning, marked by facilitated avoidance acquisition and resistance to extinction.These results suggest that hippocampal dysfunction enhances the development of persistent avoidance responding and, thus, may confer vulnerability to the development of anxiety disorders and PTSD.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology and Neurosciences, Rutgers - New Jersey Medical School, Rutgers, The State University of New Jersey , Newark, NJ , USA.

ABSTRACT
The hippocampus has been implicated in anxiety disorders and post-traumatic stress disorder (PTSD); human studies suggest that a dysfunctional hippocampus may be a vulnerability factor for the development of PTSD. In the current study, we examined the effect of hippocampal damage in avoidance learning, as avoidance is a core symptom of all anxiety disorders. First, the effect of hippocampal damage on avoidance learning was investigated in outbred Sprague Dawley (SD) rats. Second, the function of the hippocampus in Wistar-Kyoto (WKY) rats was compared to SD rats. The WKY rat is an animal model of behavioral inhibition, a risk factor for anxiety, and demonstrates abnormal avoidance learning, marked by facilitated avoidance acquisition and resistance to extinction. The results of the current study indicate that hippocampal damage in SD rats leads to impaired extinction of avoidance learning similar to WKY rats. Furthermore, WKY rats have reduced hippocampal volume and impaired hippocampal synaptic plasticity as compared to SD rats. These results suggest that hippocampal dysfunction enhances the development of persistent avoidance responding and, thus, may confer vulnerability to the development of anxiety disorders and PTSD.

No MeSH data available.


Related in: MedlinePlus