Biology subjects

Bailey, M. C. D.

Publications and source records attributed to Bailey, M. C. D..

3 recordsLinked to original sources

bioRxiv2026

Impacts and interactions of stress, noradrenaline and serotonin signalling on probabilistic reversal learning

RationaleEarly life stress (ELS) is acknowledged to underlie cognitive and emotional abnormalities linked to stress-related mood disorders. ELS can lead to persistent biases in how uncertain feedback is processed to affect the flexibility of decision-making. Objectives(1) To investigate the effects of ELS on the flexibility of rats trained on a serial probabilistic reversal learning (PRL) task involving spurious positive and negative feedback. (2) To elucidate the involvement of the stress hormone corticosterone and the noradrenergic and serotonergic systems in modulating how ELS affects PRL. MethodsMale and female rats were intermittently separated from maternal care on postnatal days five to nineteen, inclusively. As adults, the same rats were trained on a deterministic reversal learning task involving certain rewarded or non-rewarded outcomes followed by a PRL task where correct and incorrect responses were rewarded on 80% and 20% of trials, respectively. Dose-dependent effects of the beta-blocker, propranolol, selective serotonin reuptake inhibitor, citalopram and corticosterone were subsequently determined. ResultsELS resulted in an increased responsivity to feedback, specifically in males making more win-stay responses following a reward, that was associated with an increased punishment learning rate. In both control and MS rats, propranolol increased feedback sensitivity, but delayed updating following a rule switch. In contrast, neither citalopram nor corticosterone significantly affected reversal learning. ConclusionsELS is sufficient to cause persistent changes in how feedback is processed by male rats on a reversal learning task. Activation of beta-adrenergic receptors may be necessary for updating learned associations during decision-making involving uncertain feedback.

neuroscience↗

bioRxiv2026

Expression levels of α5 subunit-containing GABA-A receptors in the prelimbic cortex are associated with visual perceptual learning

Perceptual learning is a dynamic process involving the acquisition and integration of sensory information necessary for adaptive decision making. Resolving the neural basis of perceptual learning may have relevance for our understanding of schizophrenia and other neurodevelopmental disorders that implicate impaired perceptual acuity. We developed a novel touchscreen task that utilizes orientation discrimination and variable attentional load to elucidate the perceptual and attentional components of visual perceptual learning (VPL) in male and female rats. Based on previous evidence we hypothesised that individual variation in VPL may depend in part on inhibitory neurotransmission mediated by {gamma}-amino butyric acid (GABA). Segregating subjects based on poor and good learning after task pretraining revealed dose-dependent improvements in VPL in poor learners following the administration of an 5 subunit specific GABA-A (GABRA5) positive allosteric modulator (Alogabat) and a GABA-B agonist (R-baclofen) early in learning. Poor VPL performance was associated with significantly reduced GABRA5 mRNA expression in dorsal regions of the prefrontal cortex (PFC), notably the prelimbic cortex. Decreased GABRA5 expression in this region was co-localized to somatostatin- and parvalbumin-expressing interneurons. These findings reveal a potential link between GABRA5 expression in selective PFC populations of inhibitory interneurons and the speed and acuity of VPL. Significance statementCortical inhibitory microcircuits underlie visual perceptual learning (VPL) and may contribute to altered perceptual learning in neurodevelopmental disorders. However, the mechanisms underlying VPL are poorly understood. This study implemented a translationally relevant touchscreen task to assess visual perception and attention. We report that 5-subunit containing GABA-A receptors (GABRA5) are decreased in expression in the prelimbic subregion of the prefrontal cortex in animals that are slower to acquire the VPL task compared with animals showing superior VPL. We also report that VPL can be improved in a subset of poor learning animals by a positive allosteric modulator of GABRA5. These findings suggest that GABRA5 may be a potential therapeutic target to improve visual perception in schizophrenia and other neurodevelopmental disorders.

neuroscience↗

bioRxiv2022

Combining SLA 3D printing and soft lithography for fast, versatile, and accessible high-resolution fabrication of customised multiscale cell culture devices with complex designs

Cell culture devices, such as microwells and microfluidic chips, are designed to increase the complexity of cell-based models whilst retaining control over culture conditions and have become indispensable platforms for biological systems modelling. From microtopography, microwells, plating devices and microfluidic systems to larger constructs for specific applications such as live imaging chamber slides, a wide variety of culture devices with different geometries have become indispensable in biology laboratories. However, while their application in biological projects is increasing exponentially, due to a combination of the techniques and tools required for their manufacture, and the physical science background sometimes needed, the design and fabrication of such devices directly by biological labs remains a relatively high investment in terms of costs, use of facilities, needed collaborations and time. Whilst commercially available systems are available, these are also often costly, and importantly lack the potential for customisation by each single lab. This combination of factors still limits widespread application of microfabricated custom devices in most biological wet labs. Capitalising on recent important advancements in the fields of bioengineering and microfabrication, and taking advantage of low-cost, high-resolution desktop resin 3D printers combined with PDMS soft lithography, we have developed an optimised low-cost and highly reproducible microfabrication pipeline, capable of generating a wide variety of customisable devices for cell culture and tissue engineering in an easy, fast reproducible way for a fraction of the cost of conventional microfabrication or commercial alternatives. This protocol is designed specifically to be a resource for biological labs with little to none prior exposure to these fields technique and enables the manufacture of complex devices across the {micro}m to cm scale. We provide a ready-to-go pipeline for the efficient treatment of resin-based 3D printed constructs for PDMS curing, using a combination of curing steps, washes and surface treatments. Together with the extensive characterisation of the fabrication pipeline, we show the utilization of this system to a variety of applications and use cases relevant to biological experiments, ranging from micro topographies for cell alignments to complex multi-part hydrogel culturing systems. This methodology can be easily adopted by any wet lab, irrespective of prior expertise or resource availability and will enable the wide adoption of tailored microfabricated devices across many fields of biology.

bioengineering↗