Biology subjects

Albers, H. E.

Publications and source records attributed to Albers, H. E..

5 recordsLinked to original sources

bioRxiv2025

Sex differences in the neural circuitry of aggression

The social behavior neural network (SBNN) is a circuit composed of reciprocally connected limbic structures that regulate a range of social behaviors, including aggression. Although both males and females of many species display aggressive behavior, studies of the neural circuitry underlying aggression have focused almost exclusively on males. In the present study, we investigated sex differences in neuronal activation of the neural circuitry controlling aggression in Syrian hamsters (Mesocricetus auratus). We employed c-Fos immunohistochemistry to quantify neuronal activation following aggressive encounters between same-sex male and female dyads. Animals were tested in their home cage either alone (n=7 per sex) or with a same-sex, non-aggressive intruder (n=7 per sex) for 10 minutes. Our data revealed substantial sex differences in the neuronal activation of the SBNN following aggression. In some regions, neuronal activity changed in opposite directions in males and females compared to controls (e.g., posterior lateral septum), while in others, there was a change in neuronal activation in only one sex (e.g., medial amygdala). These findings support the hypothesis that the neural circuitry regulating aggression exhibits marked sexual differentiation. HighlightsO_LIThe neural circuitry regulating aggression was differentially activated in males and females following aggressive encounters C_LIO_LISeveral brain regions exhibited opposite patterns of activation in males and females following aggression C_LIO_LIOnly the BNST had the same pattern of changes in neural activity in males and females following aggression C_LI

neuroscience↗

bioRxiv2025

Comparative gene editing reduces dopamine receptor levels across rodent species

Translational challenges in neuroscience originate from species-specific differences that limit the generalizability of experimental findings. Comparative approaches can help distinguish conserved from species-specific mechanisms, but their application has been limited by the lack of molecular tools beyond traditional model organisms, complicating direct comparisons of conserved and divergent mechanisms of neural function. This gap is particularly evident for the dopaminergic system, a key regulator of motivated behaviors across species and the principal pharmacological target for current psychotherapies. Building on our recent development of comparative gene editing, we here present an adeno-associated virus-mediated CRISPR/Cas9 strategy to reduce in vivo dopamine receptors D1 and D2 levels across the rodent phylogeny. Using this approach, we achieved specific reduction of receptor levels in three rodent species (house mouse, prairie vole, and Syrian hamster), which we demonstrate with radioactive ligand binding assays. This toolkit expands the reach of comparative gene editing approaches, enabling functional investigation of the dopaminergic system across rodent species. Thereby, it supports comparative neuroscience by facilitating the identification of conserved versus species-specific neural mechanisms with enhanced translational potential.

neuroscience↗

bioRxiv2024

Distinct subcircuits within the mesolimbic dopamine system encode the salience and valence of social stimuli

The mesolimbic dopamine (DA) system (MDS) is the canonical "reward" pathway that has been studied extensively in the context of the rewarding properties of sex, food, and drugs of abuse. In contrast, very little is known about the role of the MDS in the processing of the rewarding and aversive properties of social stimuli. Social interactions can be characterized by their salience (i.e., importance) and their rewarding or aversive properties (i.e., valence). Here, we test the novel hypothesis that projections from the medial ventral tegmental area (VTA) to the nucleus accumbens (NAc) core codes for the salience of social stimuli through the phasic release of DA in response to both rewarding and aversive social stimuli. In contrast, we hypothesize that projections from the lateral VTA to the NAc shell codes for the rewarding properties of social stimuli by increasing the tonic release of DA and the aversive properties of social stimuli by reducing the tonic release of DA. Using DA amperometry, which monitors DA signaling with a high degree of temporal and anatomical resolution, we measured DA signaling in the NAc core or shell while rewarding and aversive social interactions were taking place. These findings, as well as additional anatomical and functional studies, provide strong support for the proposed neural circuitry underlying the response of the MDS to social stimuli. Together, these data provide a novel conceptualization of how the functional and anatomical heterogeneity within the MDS detect and distinguish between social salience, social reward, and social aversion. Significance StatementSocial interactions of both positive and negative valence are highly salient stimuli that profoundly impact social behavior and social relationships. Although DA projections from the VTA to the NAc are involved in reward and aversion little is known about their role in the saliency and valence of social stimuli. Here, we report that DA projections from the mVTA to the NAc core signal the salience of social stimuli, whereas projections from the lVTA to the NAc shell signal valence of social stimuli. This work extends our current understanding of the role of DA in the MDS by characterizing its subcircuit connectivity and associated function in the processing of rewarding and aversive social stimuli.

neuroscience↗

bioRxiv2020

Estrogen withdrawal alters oxytocin signaling in the paraventricular hypothalamus and dorsal raphe nucleus to increase postpartum anxiety

BackgroundEstrogen increases dramatically during pregnancy, but quickly drops below pre-pregnancy levels at birth and remains suppressed during the postpartum period. Clinical and rodent work suggests that this postpartum drop in estrogen results in an "estrogen withdrawal" state that is related to changes in affect, mood, and behavior. Most studies examining the effect of estrogen withdrawal on the brain have focused solely on the hippocampus. MethodsWe used a hormone-simulated pseudopregnancy model in Syrian hamsters, a first for this species. Ovariectomized females were given daily injections to approximate hormone levels during gestation and then withdrawn from estrogen to simulate postpartum estrogen withdrawal. Subjects were tested for behavioral assays of anxiety and anhedonia during estrogen withdrawal. Following sacrifice, neuroplasticity in oxytocin-producing neurons in the paraventricular nucleus of the hypothalamus (PVH) and its efferent targets was measured. ResultsEstrogen-withdrawn females had increased anxiety-like behaviors in the elevated plus and open field, but did not differ from controls in sucrose preference. Furthermore, estrogen-withdrawn females had more oxytocin-immunoreactive cells and oxytocin mRNA in the PVH, as well as an increase in oxytocin receptor density in the dorsal raphe nucleus (DRN). Finally, blocking oxytocin receptors in the DRN during estrogen withdrawal prevented the high-anxiety behavioral phenotype in estrogen-withdrawn females. ConclusionsEstrogen withdrawal alters oxytocin signaling in the PVH and DRN to increase anxiety-like behavior during the postpartum period. More broadly, these experiments suggest Syrian hamsters as a novel organism in which to model the effects of postpartum estrogen withdrawal on the brain and anxiety-like behavior.

neuroscience↗

bioRxiv2020

Binding affinities of oxytocin, vasopressin, and Manning Compound at oxytocin and V1a receptors in Syrian hamster brains

Oxytocin (OT) and arginine vasopressin (AVP), as well as synthetic ligands targeting their receptors (OTR, V1aR), are used in a wide variety of research contexts, but typically their pharmacological properties are determined in only a few species. Syrian hamsters (Mesocricetus auratus) have a long history of use as a behavioral and biomedical model for the study of oxytocin and vasopressin, and more recently, hamsters have been used to investigate behavioral consequences of OT-mediated activation of V1aRs. We sought to determine the binding affinities of OT, AVP, and the selective V1aR antagonist, Manning compound, in OTRs and V1aRs found in hamster brains. We performed saturation binding asays to determine the Kd values for the selective OTR and V1aR radioligands, [125I]OVTA and [125I]LVA in hamster brains. We then performed competition binding assays to determine Ki values for OT, AVP, and Manning compond at both the OTR and V1aR. We found that OT and AVP each had the highest affinity for their canonical receptors (OT-OTR Ki=4.28 nM; AVP-V1ar Ki=4.70 nM), and had the lowest affinity for their non-canonical ligands (OT-V1aR=495.2nM; AVP-OTR Ki=36.1 nM). Manning compound had the highest affinity for the V1aR (MC-V1aR Ki=6.87 nM; MC-OTR Ki=213.8 nM), but Manning compound was not as selective for the V1aR as has been reported in rat receptor. When comparing these data to previously published work, we found that the promiscuity of the V1aR in hamsters with respect to oxytocin and vasopressin binding is more similar to the promiscuity of the human V1aR than the rat V1aR receptor. Moreover, the selectivity of oxytocin at hamster receptors is more similar to the selectivity of oxytocin at human receptors than the selectivity of oxytocin at rat receptors. These data highlight the importance of determining the pharmacological properties of behaviorally relevant compounds in diverse models species.

neuroscience↗