Photoperiodic Co-Regulation of Kisspeptin, Neurokinin B and Dynorphin in the Hypothalamus of a Seasonal Rodent
Research output: Contribution to journal › Journal article › Research › peer-review
Standard
Photoperiodic Co-Regulation of Kisspeptin, Neurokinin B and Dynorphin in the Hypothalamus of a Seasonal Rodent. / Bartzen-Sprauer, J; Klosen, P; Ciofi, P; Mikkelsen, J D; Simonneaux, V.
In: Journal of Neuroendocrinology, Vol. 26, No. 8, 08.2014, p. 510-520.Research output: Contribution to journal › Journal article › Research › peer-review
Harvard
APA
Vancouver
Author
Bibtex
}
RIS
TY - JOUR
T1 - Photoperiodic Co-Regulation of Kisspeptin, Neurokinin B and Dynorphin in the Hypothalamus of a Seasonal Rodent
AU - Bartzen-Sprauer, J
AU - Klosen, P
AU - Ciofi, P
AU - Mikkelsen, J D
AU - Simonneaux, V
N1 - © 2014 British Society for Neuroendocrinology.
PY - 2014/8
Y1 - 2014/8
N2 - In many species, sexual activity varies on a seasonal basis. Kisspeptin (Kp), a hypothalamic neuropeptide acting as a strong activator of gonadotrophin-releasing hormone neurones, plays a critical role in this adaptive process. Recent studies report that two other neuropeptides, namely neurokinin B (NKB) and dynorphin (DYN), are co-expressed with Kp (and therefore termed KNDy neurones) in the arcuate nucleus and that these peptides are also considered to influence GnRH secretion. The present study aimed to establish whether hypothalamic NKB and DYN expression is photoperiod-dependent in a seasonal rodent, the Syrian hamster, which exhibits robust seasonal rhythms in reproductive activity. The majority of Kp neurones in the arcuate nucleus co-express NKB and DYN and the expression of all three peptides is decreased under a short (compared to long) photoperiod, leading to a 60% decrease in the number of KNDy neurones under photo-inhibitory conditions. In seasonal rodents, RFamide-related peptide (RFRP) neurones of the dorsomedial hypothalamus are also critical for seasonal reproduction. Interestingly, NKB and DYN are also expressed in the dorsomedial hypothalamus but do not co-localise with RFRP-immunoreactive neurones, and the expression of both NKB and DYN is higher under a short photoperiod, which is opposite to the short-day inhibition of RFRP expression. In conclusion, the present study shows that NKB and DYN display different photoperiodic variations in the Syrian hamster hypothalamus. In the arcuate nucleus, NKB and DYN, together with Kp, are down-regulated under a short photoperiod, whereas, in the dorsomedial hypothalamus, NKB and DYN are up-regulated under a short photoperiod.
AB - In many species, sexual activity varies on a seasonal basis. Kisspeptin (Kp), a hypothalamic neuropeptide acting as a strong activator of gonadotrophin-releasing hormone neurones, plays a critical role in this adaptive process. Recent studies report that two other neuropeptides, namely neurokinin B (NKB) and dynorphin (DYN), are co-expressed with Kp (and therefore termed KNDy neurones) in the arcuate nucleus and that these peptides are also considered to influence GnRH secretion. The present study aimed to establish whether hypothalamic NKB and DYN expression is photoperiod-dependent in a seasonal rodent, the Syrian hamster, which exhibits robust seasonal rhythms in reproductive activity. The majority of Kp neurones in the arcuate nucleus co-express NKB and DYN and the expression of all three peptides is decreased under a short (compared to long) photoperiod, leading to a 60% decrease in the number of KNDy neurones under photo-inhibitory conditions. In seasonal rodents, RFamide-related peptide (RFRP) neurones of the dorsomedial hypothalamus are also critical for seasonal reproduction. Interestingly, NKB and DYN are also expressed in the dorsomedial hypothalamus but do not co-localise with RFRP-immunoreactive neurones, and the expression of both NKB and DYN is higher under a short photoperiod, which is opposite to the short-day inhibition of RFRP expression. In conclusion, the present study shows that NKB and DYN display different photoperiodic variations in the Syrian hamster hypothalamus. In the arcuate nucleus, NKB and DYN, together with Kp, are down-regulated under a short photoperiod, whereas, in the dorsomedial hypothalamus, NKB and DYN are up-regulated under a short photoperiod.
KW - Animals
KW - Arcuate Nucleus of Hypothalamus
KW - Cricetinae
KW - Dorsomedial Hypothalamic Nucleus
KW - Dynorphins
KW - Gene Expression Regulation
KW - Kisspeptins
KW - Male
KW - Mesocricetus
KW - Neurokinin B
KW - Neurons
KW - Neuropeptides
KW - Photoperiod
KW - Seasons
U2 - 10.1111/jne.12171
DO - 10.1111/jne.12171
M3 - Journal article
C2 - 24935671
VL - 26
SP - 510
EP - 520
JO - Journal of Neuroendocrinology
JF - Journal of Neuroendocrinology
SN - 0953-8194
IS - 8
ER -
ID: 138185808