Behavioral and Neuroendocrine Indicators of Well-being in Farm and Laboratory Mammals

2017

Eur J of Neuroscience

Doe rabbits nurse the litter only once a day, for around 3 min, with circa 24-h periodicity. To explore the participation of the paraventricular nucleus (PVN) in regulating this behavior, we lesioned it bilaterally with kainic acid on lactation day 7. Bilateral lesions, comprising less than 50% of the total PVN volume, abolished nursing behavior (4/8 does) or severely disrupted its normal periodicity (4/8 does). In the latter case, duration of nursing bouts was normal. Body weight, food and water intake were not significantly affected by bilateral PVN lesions. Unilateral lesions of the PVN or lesions located outside this nucleus did not significantly alter nursing periodicity or any other behavioral parameter. Results indicate an important role of the PVN for (i) maintaining maternal behavior, and (ii) the periodic display of nursing across lactation in rabbits.

Section: Methodsmentioning

confidence: 97%

“…They were provided with 500 mL of water and 500 g of rabbit pellets (Conejina, Purina TM ) per day (see below). Throughout this work, animal care adhered to the Law for the Protection of Animals from Mexico (NOM-062-200-1999) in accordance with international guidelines regarding animal research (Gonz alez-Mariscal et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

Bilateral lesions of the paraventricular hypothalamic nucleus disrupt nursing behavior in rabbits

Domínguez

Aguilar‐Roblero

2017

Eur J of Neuroscience

“…To allow the construction of a maternal nest within the wooden box, 150 g of straw was placed inside the female's cage on pregnancy days 24 and 29, as described earlier (González‐Mariscal, Díaz‐Sánchez, Melo, Beyer, & Rosenblatt, ). Throughout this experiment, animal care adhered to the Law for the Protection of Animals (Mexico) and with international guidelines regarding animal research (González‐Mariscal, Sisto‐Burt, & Nowak, ).…”

Section: Methodsmentioning

confidence: 99%

Long‐lasting behavioral and neuroendocrine changes provoked in rabbits by cancelling a single nursing bout in early lactation

Fernández

Chavira-Ramírez

Developmental Psychobiology

2019

To restore estrus in lactating doe rabbits, nursing was prevented on lactation day 10 and allowed again from day 12 onward. This “biostimulation” procedure, used to accelerate reproduction, allows kit survival despite a 48 hr fast. Yet, the consequences of “biostimulation” on their psychobiological and neuroendocrine development are largely unknown. Therefore, we determined, in adult males and females, tested in the morning or afternoon: corticosteroid secretion (baseline and reactive), sexual behavior, and responses in six tests measuring stress/anxiety. The latter were not affected by maternal deprivation or time of testing in either sex. The lordosis quotient was reduced in deprived does (relative to controls), an effect eliminated when only non‐kins (of both groups) were compared. Deprived males showed altered sexual behavior, evidenced by a large number of mounts not culminating in ejaculation. Corticosterone and cortisol secretion increased (relative to baseline) following i.m. saline in all groups, but the magnitude of the response was affected by maternal deprivation, time of day, and sex. Results indicate that particular behaviors and reactivity to stress have different thresholds regarding the effects of mother–litter separation in early lactation.

“…Purina™ rabbit pellets and water were available ad lib.. The experimental procedures used throughout complied with the Law for the Protection of Animals (Mexico) and with international guidelines regarding animal welfare …”

Section: Methodsmentioning

confidence: 99%

Maternal responsiveness to suckling is modulated by time post‐nursing: A behavioural and c‐Fos/oxytocin immunocytochemistry study in rabbits

Jiménez

2019

J Neuroendocrinology

Doe rabbits nurse once/day for approximately 3 minutes, with circadian periodicity, inside the nest box. The amount of suckling received at each bout regulates this behaviour because reducing the litter size to four kits or less disrupts nursing circadian periodicity and increases suckling bout duration. Additionally, the likelihood that does will nurse kits at a given time of day depends on the time elapsed since the last suckling episode and the litter size nursed then. We hypothesised that the time elapsed since the last nursing would impact the number of c‐Fos immunoreactive (IR) cells observed after suckling five kits and also that observed before the next nursing (“no kits”). Suckling significantly increased, relative to “no kits”, the number of c‐Fos‐IR cells in the medial preoptic area and lateral septum but not in the bed nucleus of the stria terminalis (BNST), suprachiasmatic nucleus or ventromedial hypothalamus in does nursing at 18 or 24 hours after the previous bout. No effects of suckling were observed in mothers nursing at 6 hours. Does given kits at 3 hours post last suckling refused to nurse but, in the remaining three groups, all does nursed normally. At “no kits”, more c‐Fos‐IR cells were seen (in all regions except the BNST) in does given kits at 24 hours after the last nursing and killed 1 hour later (ie, 4 hours after lights on) than in those killed earlier. The percentage of oxytocinergic (OT) cells co‐expressing c‐Fos was not modified by nursing in the paraventricular or supraoptic nuclei but, in the latter, the largest number of total OT‐IR cells occurred at 18 and 24 hours post‐last nursing. In conclusion, the responsiveness of particular forebrain regions involved in regulating circadian rhythms, lactation, and maternal behaviour is modulated by suckling and time of day.