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Investigating the Role of Hippocampal BDNF in Anxiety Vulnerability Using Classical Eyeblink Conditioning.

Janke KL, Cominski TP, Kuzhikandathil EV, Servatius RJ, Pang KC - Front Psychiatry (2015)

Bottom Line: Individuals with BI show facilitated acquisition of the classically conditioned eyeblink response (CCER) as compared to non-BI individuals, and a similar pattern is seen in an animal model of BI, the Wistar-Kyoto (WKY) rat.To determine whether reduced hippocampal BDNF in WKY rats was a contributing factor for their facilitated CCER, BDNF or saline infusions were given bilaterally into the dentate gyrus region 1 h prior to training.Together, these results suggest that inherent differences in the BDNF system play a critical role in the facilitated associative learning exhibited by WKY rats, and potentially individuals with BI.

View Article: PubMed Central - PubMed

Affiliation: Research Service, Neurobehavioral Research Laboratory, VA New Jersey Heath Care System , East Orange, NJ , USA ; Graduate School of Biomedical Sciences, New Jersey Medical School, Rutgers Biomedical and Health Sciences , Newark, NJ , USA.

ABSTRACT
Dysregulation of brain-derived neurotrophic factor (BDNF), behavioral inhibition temperament (BI), and small hippocampal volume have been linked to anxiety disorders. Individuals with BI show facilitated acquisition of the classically conditioned eyeblink response (CCER) as compared to non-BI individuals, and a similar pattern is seen in an animal model of BI, the Wistar-Kyoto (WKY) rat. The present study examined the role of hippocampal BDNF in the facilitated delay CCER of WKY rats. Consistent with earlier work, acquisition was facilitated in WKY rats compared to the Sprague Dawley (SD) rats. Facilitated acquisition was associated with increased BDNF, TrkB, and Arc mRNA in the dentate gyrus of SD rats, but learning-induced increases in BDNF and Arc mRNA were significantly smaller in WKY rats. To determine whether reduced hippocampal BDNF in WKY rats was a contributing factor for their facilitated CCER, BDNF or saline infusions were given bilaterally into the dentate gyrus region 1 h prior to training. BDNF infusion did not alter the acquisition of SD rats, but significantly dampened the acquisition of CCER in the WKY rats, such that acquisition was similar to SD rats. Together, these results suggest that inherent differences in the BDNF system play a critical role in the facilitated associative learning exhibited by WKY rats, and potentially individuals with BI. Facilitated associative learning may represent a vulnerability factor in the development of anxiety disorders.

No MeSH data available.


Related in: MedlinePlus

Strain differences in classical eyeblink conditioning. Wistar-Kyoto (WKY) and Sprague Dawley (SD) rats were trained in delayed classical conditioning of the eyeblink response. A session consisted of five blocks of 20 trials. WKY rats acquired eyeblink conditioning significantly faster and to a greater extent than SD rats, as demonstrated by higher levels of conditioned responses.
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Figure 1: Strain differences in classical eyeblink conditioning. Wistar-Kyoto (WKY) and Sprague Dawley (SD) rats were trained in delayed classical conditioning of the eyeblink response. A session consisted of five blocks of 20 trials. WKY rats acquired eyeblink conditioning significantly faster and to a greater extent than SD rats, as demonstrated by higher levels of conditioned responses.

Mentions: Sprague Dawley (n = 7) and WKY (n = 8) rats were trained in one session of delay classical conditioning of the eyeblink response followed by sacrifice for assessment of hippocampal BDNF, TrkB, and Arc mRNA. Due to problems with EMG recording, 1 SD and 2 WKY rats could not be evaluated for behavior; these rats showed clear eyeblink to periorbital electrical stimulation US and should demonstrate classical conditioning similar to other rats. Therefore, all rats were included in the mRNA analysis. Acquisition of classical conditioning was significantly faster and performed to a greater degree in WKY rats compared to SD rats, main effect of strain [F(1, 10) = 5.02, p < 0.05] (Figure 1), replicating previous results (45). Overall, general learning was demonstrated by a main effect of block [F(4, 40) = 8.38, p < 0.001]. No interaction between block and strain was observed. Ninety to one hundred and twenty minutes following the conditioning sessions, rats were sacrificed and the hippocampus removed, subdivided, and stored for subsequent analysis by qRT-PCR.


Investigating the Role of Hippocampal BDNF in Anxiety Vulnerability Using Classical Eyeblink Conditioning.

Janke KL, Cominski TP, Kuzhikandathil EV, Servatius RJ, Pang KC - Front Psychiatry (2015)

Strain differences in classical eyeblink conditioning. Wistar-Kyoto (WKY) and Sprague Dawley (SD) rats were trained in delayed classical conditioning of the eyeblink response. A session consisted of five blocks of 20 trials. WKY rats acquired eyeblink conditioning significantly faster and to a greater extent than SD rats, as demonstrated by higher levels of conditioned responses.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4513557&req=5

Figure 1: Strain differences in classical eyeblink conditioning. Wistar-Kyoto (WKY) and Sprague Dawley (SD) rats were trained in delayed classical conditioning of the eyeblink response. A session consisted of five blocks of 20 trials. WKY rats acquired eyeblink conditioning significantly faster and to a greater extent than SD rats, as demonstrated by higher levels of conditioned responses.
Mentions: Sprague Dawley (n = 7) and WKY (n = 8) rats were trained in one session of delay classical conditioning of the eyeblink response followed by sacrifice for assessment of hippocampal BDNF, TrkB, and Arc mRNA. Due to problems with EMG recording, 1 SD and 2 WKY rats could not be evaluated for behavior; these rats showed clear eyeblink to periorbital electrical stimulation US and should demonstrate classical conditioning similar to other rats. Therefore, all rats were included in the mRNA analysis. Acquisition of classical conditioning was significantly faster and performed to a greater degree in WKY rats compared to SD rats, main effect of strain [F(1, 10) = 5.02, p < 0.05] (Figure 1), replicating previous results (45). Overall, general learning was demonstrated by a main effect of block [F(4, 40) = 8.38, p < 0.001]. No interaction between block and strain was observed. Ninety to one hundred and twenty minutes following the conditioning sessions, rats were sacrificed and the hippocampus removed, subdivided, and stored for subsequent analysis by qRT-PCR.

Bottom Line: Individuals with BI show facilitated acquisition of the classically conditioned eyeblink response (CCER) as compared to non-BI individuals, and a similar pattern is seen in an animal model of BI, the Wistar-Kyoto (WKY) rat.To determine whether reduced hippocampal BDNF in WKY rats was a contributing factor for their facilitated CCER, BDNF or saline infusions were given bilaterally into the dentate gyrus region 1 h prior to training.Together, these results suggest that inherent differences in the BDNF system play a critical role in the facilitated associative learning exhibited by WKY rats, and potentially individuals with BI.

View Article: PubMed Central - PubMed

Affiliation: Research Service, Neurobehavioral Research Laboratory, VA New Jersey Heath Care System , East Orange, NJ , USA ; Graduate School of Biomedical Sciences, New Jersey Medical School, Rutgers Biomedical and Health Sciences , Newark, NJ , USA.

ABSTRACT
Dysregulation of brain-derived neurotrophic factor (BDNF), behavioral inhibition temperament (BI), and small hippocampal volume have been linked to anxiety disorders. Individuals with BI show facilitated acquisition of the classically conditioned eyeblink response (CCER) as compared to non-BI individuals, and a similar pattern is seen in an animal model of BI, the Wistar-Kyoto (WKY) rat. The present study examined the role of hippocampal BDNF in the facilitated delay CCER of WKY rats. Consistent with earlier work, acquisition was facilitated in WKY rats compared to the Sprague Dawley (SD) rats. Facilitated acquisition was associated with increased BDNF, TrkB, and Arc mRNA in the dentate gyrus of SD rats, but learning-induced increases in BDNF and Arc mRNA were significantly smaller in WKY rats. To determine whether reduced hippocampal BDNF in WKY rats was a contributing factor for their facilitated CCER, BDNF or saline infusions were given bilaterally into the dentate gyrus region 1 h prior to training. BDNF infusion did not alter the acquisition of SD rats, but significantly dampened the acquisition of CCER in the WKY rats, such that acquisition was similar to SD rats. Together, these results suggest that inherent differences in the BDNF system play a critical role in the facilitated associative learning exhibited by WKY rats, and potentially individuals with BI. Facilitated associative learning may represent a vulnerability factor in the development of anxiety disorders.

No MeSH data available.


Related in: MedlinePlus