CD38 in the nucleus accumbens and oxytocin are related to paternal behavior in mice.
BACKGROUND
Mammalian sires participate in infant care. We previously demonstrated that sires of a strain of nonmonogamous laboratory mice initiate parental retrieval behavior in response to olfactory and auditory signals from the dam during isolation in a new environment. This behavior is rapidly lost in the absence of such signals when the sires are caged alone. The neural circuitry and hormones that control paternal behavior are not well-understood. CD38, a membrane glycoprotein, catalyzes synthesis of cyclic ADP-ribose and facilitates oxytocin (OT) secretion due to cyclic ADP-ribose-dependent increases in cytosolic free calcium concentrations in oxytocinergic neurons in the hypothalamus. In this paper, we studied CD38 in the nucleus accumbens (NAcc) and the role of OT on paternal pup retrieval behavior using CD38 knockout (CD38-/-) mice of the ICR strain.


RESULTS
CD38-/- sires failed to retrieve when they were reunited with their pups after isolation together with the mate dams, but not with pup, in a novel cage for 10 min. CD38-/- sires treated with a single subcutaneous injection of OT exhibited recovery in the retrieval events when caged with CD38-/- dams treated with OT. We introduced human CD38 in the NAcc of CD38-/- sires using a lentiviral infection technique and examined the effects of local expression of CD38. Pairs of knockout dams treated with OT and sires expressing CD38 in the NAcc showed more retrieval (83% of wild-type sire levels). Complete recovery of retrieval was obtained in sires with the expression of CD38 in the NAcc in combination with OT administration. Other paternal behaviors, including pup grooming, crouching and huddling, were also more common in CD38-/- sires with CD38 expression in the NAcc compared with those in CD38-/- sires without CD38 expression in the NAcc.


CONCLUSIONS
CD38 in the NAcc and OT are critical in paternal behavior.
Kanazawa University Center for Child Mental Development, Kanazawa 920-8640, Japan. haruhiro@med.kanazawa-u.ac.jp.
Shirin
S
Akther
Natalia
N
Korshnova
Jing
J
Zhong
Mingkun
M
Liang
Stanislav M
SM
Cherepanov
Olga
O
Lopatina
Yulia K
YK
Komleva
Alla B
AB
Salmina
Tomoko
T
Nishimura
Azam Akm
AA
Fakhrul
Hirokazu
H
Hirai
Ichiro
I
Kato
Yasuhiko
Y
Yamamoto
Shin
S
Takasawa
Hiroshi
H
Okamoto
Haruhiro
H
Higashida
D051997:ADP-ribosyl Cyclase 1 / Q000378:metabolism*; D000818:Animals; D002755:Choice Behavior / Q000187:drug effects; D005260:Female; D005453:Fluorescence; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006120:Grooming / Q000187:drug effects; D006801:Humans; D007211:Indoles / Q000378:metabolism; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism*; D051379:Mice; D008813:Mice, Inbred ICR; D018345:Mice, Knockout; D009714:Nucleus Accumbens / Q000187:drug effects / Q000378:metabolism*; D010121:Oxytocin / Q000378:metabolism* / Q000494:pharmacology; D010332:Paternal Behavior / Q000187:drug effects; D011930:Reaction Time / Q000187:drug effects; D013395:Sucrose / Q000494:pharmacology; D014162:Transfection
D007211:Indoles; D008562:Membrane Glycoproteins; D049452:Green Fluorescent Proteins; C007293:DAPI; D010121:Oxytocin; D013395:Sucrose; C498155:Cd38 protein, mouse; D051997:ADP-ribosyl Cyclase 1