Article Figures & Data
Figures
- Figure 1.
Experimental timelines and avoidance behavior in males during odor exposure. A, Timeline of treatment procedures involving F0 males. During OE1, males were exposed to either PO or CO for 30 min, three times per day for 7 d beginning 24 d prior to mating. OE2 was conducted identically except that the CO and PO exposures began 7 d prior to mating. Males from OE1 and OE2 were subjected to a PPT using sexually receptive virgin, naive females. Within 12 h of the PPT, males were bred with different receptive naive virgin females. Following confirmed mating, males were removed, and females were left undisturbed until offspring were born. B, Timeline of treatment procedures for F0 females and the F1 offspring. Birth was considered P0, and offspring were counted, sexed, and weighed before being transferred to either fresh SH or SNH, with biological mothers, until weaning. Maternal behavior (Mat Care) was scored for 1 h, five times per day for 7 d. At P21, all offspring were weighed, weaned, and placed in SH with a same-sex littermate. Play behavior was recorded in the home cage from P24 to P29, followed by exposure to the OFT and the EPM on P32 to P35. F1 OE took place on P42 with male and female offspring being exposed to either PO or CO for 30 min and then killed. Sample sizes are provided for both the F0 and F1 groups. C, Avoidance behavior in F0 male rats was significantly increased in those exposed to PO relative to those exposed to CO during OE. Data are expressed as the mean ± SEM. **p ≤ 0.005, PO different from CO.
- Figure 2.
Use of a PPT to ascertain female preference for males previously exposed to PO relative to CO. A, Schematic representation of the T-maze used for the PPT. Males were placed in the ends of arms confined by Plexiglas shields containing many holes. B, C, Female rats spent less time in the vicinity of PO-exposed males relative to CO-exposed males during the last 4 min of a partner preference test, both 1 and 17 d after the odor exposure had occurred in males. The percentage of time spent with males was calculated as the percentage of time spent with either a CO or PO male per total time spent with both CO and PO males. Data are expressed as the mean ± SEM. *p ≤ 0.05, PO different from CO.
- Figure 3.
Maternal behaviors of females housed in SNH or SH raising offspring of mates that were exposed to either PO or CO. A, Frequency of various maternal behaviors [PC, passive contact (with pups); ABN1, arched-back nursing 1 (blanket posture); 2, arched-back nursing 2; 3, arched-back nursing 3; 4, arched back nursing 4; NB, nest building; SG, self-groom (auto-groom); PR, pup retrieval] displayed by females housed in SH and SNH, collapsed across paternal condition. The inset shows schematics of the housing conditions; the SNH includes a lower burrow compartment (contained within a drawer that moves out to facilitate cleaning) and an upper section (containing food and water), with the two sections being connected by a hole (visible in the upper section). B, The frequency of LG-ABN2 behaviors was significantly increased in dams raising offspring in SNH relative to those housed in SH, but only if offspring were from PO exposed males. C, The frequency of LG-ABN3 behavior was increased in dams living in SNH relative to SH, regardless of paternal experience. D, Living in SNH reduced pup mortality relative to living in SH. Data are expressed as the mean ± SEM. *p ≤ 0.05, SNH different from SH; **p ≤ 0.005, SNH different from SH.
- Figure 4.
Weaning weight and social behavior of juvenile offspring raised by females housed in SNH or SH and sired by males exposed to either PO or CO. A, SNH rearing significantly increased weaning weight in both male and female offspring, regardless of paternal experience, with males overall weighing more than females. B, Increased social grooming occurred in female offspring, compared with male offspring, and was higher in offspring reared in SH relative to those reared in SNH. C, Males engaged in significantly more play attacks than females. D, Males also engaged in significantly more play defend behaviors relative to females. E, Evading behavior in response to play attacks was decreased overall in offspring reared in SNH relative to SH, but more specifically, CO-SH-reared offspring evaded more than PO-SH- and CO-SNH-reared offspring. Data are expressed as the mean ± SEM. Difference between indicated groups: *p ≤ 0.05; **p ≤ 0.005.
- Figure 5.
Development of fear- and anxiety-like behavior in the offspring raised by females housed in SNH or SH and sired by males exposed to either PO or CO. A, Center time in the open-field test was increased (indicative of reduced anxiety-like behavior) in offspring raised in SNH relative to those reared in SH. B, In the EPM, female offspring spent more time in the open arms relative to males. C, Overall, in the EPM, female offspring displayed less anxiety (more frequent open arm entry) than males, and, in particular, females of either the CO-SNH or PO-SH group displayed reduced anxiety relative to other groups. Data are expressed as the mean ± SEM. Interaction: difference between indicated groups, *p ≤ 0.05; **p ≤ 0.005.
- Figure 6.
Effects of 30 min exposure to either CO (F1CO) or PO (F1PO) on behavior and hypothalamic crf gene regulation of offspring raised by females housed in SNH or SH and sired by males exposed to either PO (F0PO) or CO (F0CO). A, Rearing duration was not significantly different in F1PO versus F1CO males, nor was it affected by paternal or maternal condition. B, Likewise, rearing frequency was not significantly affected by short-term exposure to PO or paternal or maternal condition in males. B, C, Both rear duration (C) and rear frequency (D) were lower in F1PO-exposed females relative to F1CO-exposed females. Beyond the main effect, rearing frequency and duration were increased in all female offspring (exposed in the short term to CO or PO) of CO fathers and mothers housed in SNH. E, Diagrammatic representation (left) and representative photomicrographs (10× objective) of DAPI-stained coronal sections showing the dissection site (white circle/arrow) in micropunched (middle) and intact (right) PVN tissue, in relation to the third ventricle (3V). F–H, H3K9ac enrichment of the crf promoter in PVN was increased in F0PO relative to F0CO offspring (F), reduced in offspring raised in SNH relative to those raised in SH (G), and increased in F1PO offspring relative to F1CO offspring (H). I, Levels crf primary transcript (hnRNA) in PVN were also increased in F1PO offspring relative to F1CO offspring. J, Levels of H3K9ac enrichment of the crf promoter and hnRNA expression were positively correlated in F1CO and F1PO offspring. Data are expressed as the mean ± SEM. Difference between indicated groups, *p ≤ 0.05; **p ≤ 0.005. Scale bar, 200 μm.
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