Maternal immune activation affects female offspring whisker movements during object exploration in a rat model of neurodevelopmental disorders.

Poly I:C rat offspring are used to investigate the effects of exposure to maternal immune activation (MIA) and have been suggested as a model of neurodevelopmental disorders (NDD). The behavioural symptoms of this model are diverse and can vary with external factors, including the choice of background strain and husbandry practices. Measuring whisker movements provides quantitative, robust measurements of sensory, motor and cognitive behaviours in rodents.

Neural mechanisms underlying psilocybin's therapeutic potential - the need for preclinical in vivo electrophysiology.

Psilocybin is a naturally occurring psychedelic compound with profound perception-, emotion- and cognition-altering properties and great potential for treating brain disorders. However, the neural mechanisms mediating its effects require in-depth investigation as there is still much to learn about how psychedelic drugs produce their profound and long-lasting effects. In this review, we outline the current understanding of the neurophysiology of psilocybin's psychoactive properties, highlighting the need for additional preclinical studies to determine its effect on neural network dynamics.

Functional ultrasound imaging of recent and remote memory recall in the associative fear neural network in mice.

Emotional learning and memory are affected in numerous psychiatric disorders. At a systems level, however, the underlying neural circuitry is not well defined. Rodent fear conditioning (FC) provides a translational model to study the networks underlying associative memory retrieval.

A triple-network organization for the mouse brain.

The triple-network model of psychopathology is a framework to explain the functional and structural neuroimaging phenotypes of psychiatric and neurological disorders. It describes the interactions within and between three distributed networks: the salience, default-mode, and central executive networks. These have been associated with brain disorder traits in patients.

Timed daily exercise remodels circadian rhythms in mice.

Regular exercise is important for physical and mental health. An underexplored and intriguing property of exercise is its actions on the body's 24 h or circadian rhythms. Molecular clock cells in the brain's suprachiasmatic nuclei (SCN) use electrical and chemical signals to orchestrate their activity and convey time of day information to the rest of the brain and body.

Quantifying how much attention rodents allocate to motivationally-salient objects with a novel object preference test.

The allocation of attention can be modulated by the emotional value of a stimulus. In order to understand the biasing influence of emotion on attention allocation further, we require an animal test of how motivational salience modulates attention. In mice, female odour triggers arousal and elicits emotional responses in males.

Synaptic biomarker reduction and impaired cognition in the sub-chronic PCP mouse model for schizophrenia.

Background: Sub-chronic phencyclidine treatment (scPCP) provides a translational rat model for cognitive impairments associated with schizophrenia (CIAS). CIAS genetic risk factors may be more easily studied in mice; however, CIAS associated biomarker changes are relatively unstudied in the scPCP mouse.

Aim: To characterize deficits in object recognition memory and synaptic markers in frontal cortex and hippocampus of the scPCP mouse.

Bursting Neurons in the Hippocampal Formation Encode Features of LFP Rhythms.

Burst spike patterns are common in regions of the hippocampal formation such as the subiculum and medial entorhinal cortex (MEC). Neurons in these areas are immersed in extracellular electrical potential fluctuations often recorded as the local field potential (LFP). LFP rhythms within different frequency bands are linked to different behavioral states.

Postnatal light alters hypothalamic-pituitary-adrenal axis function and induces a depressive-like phenotype in adult mice.

The postnatal light environment that a mouse experiences during the critical first three postnatal weeks has long-term effects on both its circadian rhythm output and clock gene expression. Furthermore, data from our lab suggest that postnatal light may also impact the hypothalamic-pituitary-adrenal (HPA) axis, which is a key regulator of stress. To test the effect of postnatal light exposure on adult stress responses and circadian rhythmicity, we raised mice under either 24-h light-dark cycles (LD), constant light (LL) or constant dark (DD) during the first three postnatal weeks.

Phase-locking of bursting neuronal firing to dominant LFP frequency components.

Neuronal firing in the hippocampal formation relative to the phase of local field potentials (LFP) has a key role in memory processing and spatial navigation. Firing can be in either tonic or burst mode. Although bursting neurons are common in the hippocampal formation, the characteristics of their locking to LFP phase are not completely understood.

Increased hippocampal excitability in the 3xTgAD mouse model for Alzheimer's disease in vivo.

Mouse Alzheimer's disease (AD) models develop age- and region-specific pathology throughout the hippocampal formation. One recently established pathological correlate is an increase in hippocampal excitability in vivo. Hippocampal pathology also produces episodic memory decline in human AD and we have shown a similar episodic deficit in 3xTg AD model mice aged 3-6 months.

Episodic-like memory is sensitive to both Alzheimer's-like pathological accumulation and normal ageing processes in mice.

Episodic memory depends on the hippocampus and is sensitive to both Alzheimer's disease (AD) pathology and normal ageing. We showed previously that 3xTgAD mice express a specific, episodic-memory deficit at 6 months of age in the What-Where-Which occasion (WWWhich) task (Davis, Easton, Eacott and Gigg, 2013). This task requires the integration of object-location and contextual cues to form an episodic-like memory.

Effects of increased spatial complexity on behavioural development and task performance in Lister Hooded rats.

Enhancing laboratory animal welfare, particularly in rodents, has been achieved through environmental enrichment in caging systems. Traditional enrichment such as adding objects has shown to impact development, reproductive and maternal performance as well as cognition. However, effects of increased spatial complexity as part of larger novel caging systems have not been investigated.

Episodic-like memory for what-where-which occasion is selectively impaired in the 3xTgAD mouse model of Alzheimer's disease.

Episodic memory loss is a defining feature of early-stage Alzheimer's disease (AD). A test of episodic-like memory for the rat, the What-Where-Which occasion task (WWWhich), requires the association of object, location, and contextual information to form an integrated memory for an event. The WWWhich task cannot be solved by use of non-episodic information such as object familiarity and is dependent on hippocampal integrity.

Inverse current source density method in two dimensions: inferring neural activation from multielectrode recordings.

The recent development of large multielectrode recording arrays has made it affordable for an increasing number of laboratories to record from multiple brain regions simultaneously. The development of analytical tools for array data, however, lags behind these technological advances in hardware. In this paper, we present a method based on forward modeling for estimating current source density from electrophysiological signals recorded on a two-dimensional grid using multi-electrode rectangular arrays.

Melanopsin contributions to irradiance coding in the thalamo-cortical visual system.

Photoreception in the mammalian retina is not restricted to rods and cones but extends to a subset of retinal ganglion cells expressing the photopigment melanopsin (mRGCs). These mRGCs are known to drive such reflex light responses as circadian photoentrainment and pupillomotor movements. By contrast, until now there has been no direct assessment of their contribution to conventional visual pathways.

Naturalistic stimulus trains evoke reproducible subicular responses both within and between animals in vivo.

Previous investigation of CA1-evoked subicular responses has used either single low-frequency pulses (LF), paired-pulses (PP), or high-frequency bursts. Here we test for the first time how subiculum responds to naturalistic stimulation trains (NSTs). We recorded CA1-evoked field potentials from dorsal rat subiculum in response to LF, PP, and two NST patterns.

The subiculum comes of age.

The subiculum has long been considered as a simple bidirectional relay region interposed between the hippocampus and the temporal cortex. Recent evidence, however, suggests that this region has specific roles in the cognitive functions and pathological deficits of the hippocampal formation. A group of 20 researchers participated in an ESF-sponsored meeting in Oxford in September, 2005 focusing on the neurobiology of the subiculum.

Constraints on hippocampal processing imposed by the connectivity between CA1, subiculum and subicular targets.

A long-held fundamental function of the rat hippocampus is to provide a spatial map of the environment. The principal hippocampal output region for spatial information is area CA1 and the major target of CA1 is the subiculum. Thus, one possible role of the subiculum is to receive, process and transmit information regarding location to areas outside the hippocampus.