Progesterone impairs social recognition in male rats

“Experiment 5 Object recognition test This paradigm was adapted from (Bevins and Besheer, 2006).”

“Specifically, dendritic spine density declines as estrogen levels fall, but they decline even faster if progesterone is administered during the decline in estrogen levels (Woolley and McEwen, 1993).”

“N IH -PA Author M anuscript N IH -PA Author M anuscript circulating levels of progesterone around 1.5 - 2 ng/ml (Auger and Vanzo, 2006;Andersen et al., 2004), compared to a range of 3 - 35 ng/ml in females that is seen throughout the rat estrus cycle (Weisz and Ward, 1980).”

“N IH -PA Author M anuscript N IH -PA Author M anuscript N IH -PA Author M anuscript 2003;Brinton et al., 2008;Auger and De Vries, 2002).”

“Additionally, while one study showed that animals lacking the AVP V1A receptor show deficits in social recognition (Bielsky et al., 2004), another lab showed that mice lacking the V1A receptor did not have impairments in this behavior (Wersinger et al., 2007).”

“…a conspecific after an initial exposure typically lasts only 30 minutes; however, subcutaneous injections of AVP in rats and mice can facilitate social recognition by lengthening this social memory to 2 hours after initial exposure to a conspecific (Dantzer et al., 1987;Bielsky and Young, 2004).”

“…a conspecific after an initial exposure typically lasts only 30 minutes; however, subcutaneous injections of AVP in rats and mice can facilitate social recognition by lengthening this social memory to 2 hours after initial exposure to a conspecific (Dantzer et al., 1987;Bielsky and Young, 2004).”

“However, this same lab showed that animals lacking AVP V1b receptors show deficits in social recognition (Wersinger et al., 2002), taken together these data suggest that mechanisms altering AVP levels or AVP signaling have a strong potential to influence this AVP-dependant behavior.”

“Experiments 2 and 3 Social Discrimination, RU486, R5020 The social discrimination paradigm was adapted from Engelmann et al. (Engelmann et al., 1995).”

“Social recognition is also enhanced by cite specific infusions of an AVP agonist or impaired by infusions of AVP antagonists directly into the lateral septum (Dantzer et al., 1988).”

“Allopregnanolone potentiates the effects of GABA at the GABAA receptor, thereby increasing its inhibitory effect, and it is through this effect that allopregnanolone influences memory as well as a number of other behaviors (Dubrovsky, 2005).”

“As numerous factors regulate social recognition memory, such as vasopressin, oxytocin and dopamine (Keverne and Curley, 2004) it is not clear if progesterone action on one or a number of these systems influences social recognition.”

“Animals treated with allopregnanolone show an increased latency to find the platform in the maze compared to controls (Johansson et al., 2002).”

“Furthermore, castration, which depletes AVP in the BST and MeA, and in projection sites of these cells, also impairs social recognition (Bluthe et al., 1990).”

“[PubMed: 12399951] Winslow JT, Camacho F. Cholinergic modulation of a decrement in social investigation following repeated contacts between mice.”

“Also, depending on the type of stressful event encountered, progesterone levels in males can approach 6 ng/ml (Andersen et al., 2004), suggesting a potential functional significance of this hormone in males.”

“In this study, progesterone treatment is associated with decreased activity in the amygdala and in the fusiform face area as measured by event-related fMRI (van Wingen et al., 2007).”

“Additionally, while one study showed that animals lacking the AVP V1A receptor show deficits in social recognition (Bielsky et al., 2004), another lab showed that mice lacking the V1A receptor did not have impairments in this behavior (Wersinger et al., 2007).”

“…task, control animals preferentially explored a novel arm; however, mice receiving infusions of allopregnanolone into the lateral ventricles for several days did not investigate a novel, previously unexplored, arm in the maze, suggesting a form of spatial memory impairment (Ladurelle et al., 2000).”

“Recent studies demonstrate that progesterone and its receptor play an important, yet understudied, role in male behavior and physiology (Wagner, 2006).”

“The vast body of our knowledge on progesterone and progestin receptor (PR) function comes from studies in females (Priest and Pfaff, 1995;Blaustein, 2008).”

“While social recognition memory is dependent upon AVP transmission in the LS (Everts and Koolhaas, 1997), perhaps nonsocial memory is dependent upon other, non-AVP dependent, mechanisms.”

“It is also important to note that progesterone might be acting to alter the expression of other steroid receptors that are important for regulating AVP expression and social recognition memory (De Vries et al., 1985) (Imwalle et al., 2002).”

“On a behavioral level, changes in progesterone levels are associated with memory impairments in rodents (Vallee et al., 2001).”

“Not surprisingly, PRs within the male brain have been reported to be expressed in areas classically associated with reproduction (Guerra-Araiza et al., 2001).”

“It is also important to note, that as males have higher levels of steroid receptor coactivators, which enhance steroid hormone action in many brain regions (Bian et al., 2011), it is likely that lower levels of progesterone are sufficient to elicit a physiological response within the male brain.”

“The preputial glands were homogenized in ice cold tris buffered saline (TBS) and then centrifuged (Thompson et al., 2007).”

“One behavior that is linked to AVP in the LS, a site that receives AVP projections from the BST and MeA, is social recognition behavior.”

“We hypothesize that the impairment in social recognition memory that we observed is mediated through the suppression in AVP levels that are seen following progesterone treatment in the BST and MeA (Auger and Vanzo, 2006).”

“Experiment 4 Olfactory tests, Food-finding test This paradigm was adapted from (Mencio-Wszalek et al., 1992).”

“The vast body of our knowledge on progesterone and progestin receptor (PR) function comes from studies in females (Priest and Pfaff, 1995;Blaustein, 2008).”

“Progesterone treatment for three days prior to testing impaired social recognition in adult male rats, at least in part by reducing vasopressin expression in the BNST, MeA and LS (Bychowski et al., 2013; Bychowski and Auger, 2012).”

“) and that progesterone may even play a direct role in male behavior in some mammals (Wagner, 2006; Bychowski and Auger, 2012).”

“…in the BST and MeA, and that progesterone impairs social recognition behavior in adult male rats, these data provide a strong link between progesterone’s actions and their potential functional significance for AVP-linked social behavior in males (Auger and Vanzo, 2006) (Bychowski and Auger, 2012).”

“PROG also impairs social recognition in male rats acting on PRs [114].”

“reported that isoflurane exposure during development and progesterone results in impaired social memory, but no influence on novel object recognition [64,65], while in this study, we found dityrosine administration impairs object recognition memory, but not social recognition.”

“…Bierbach et al. 2011; Jarcho et al. 2011; Sheehan & Tibbetts 2011; Bos & d’Ettorre 2012), but perhaps no animals have contributed to a deep understanding of social recognition more than rodents (Bielsky et al. 2005; Choleris et al. 2009; Albers 2012; Bychowski & Auger 2012; Wacker & Ludwig 2012).”

“and social recognition in adult rats [56].”

“Effects of PROG, ALLO and AG205 on PGRMC1 Expression in Basal Conditions In healthy status, overload of exogenous PROG/ALLO administration does appear to impair non-social learning and memory tasks in normal rodents (Johansson et al., 2002; Bychowski and Auger, 2012), which is in accordance with the previous observati…”

“As a result, progesterone injectionin male rats impairs social recognition 70 , which can be rescued by direct AVP infusion into LS 25 .”

“Many extra-hypothalamic AVP-synthesizing cells contain PRir, and their AVP expression is negatively influenced by progesterone (Auger and Vanzo, 2006; Rood et al., 2008) in a manner that impairs male social recognition and behavior (Bychowski and Auger, 2012).”

“For example, progesterone administration has been found to disrupt social recognition in adult males [17], while a more recent study showed the opposite [18].”