Biology subjects

Rook, N.

Publications and source records attributed to Rook, N..

3 recordsLinked to original sources

bioRxiv2025

Achieving cell-type specific transduction with adeno-associated viral vectors in pigeons

Birds are valuable models for studying learning, cognition, song, and vision, yet tools for controlling and recording brain activity with millisecond precision remain underutilized in avian research. Advances in methods such as chemogenetics, optogenetics, and in vivo imaging have transformed rodent studies but require gene delivery techniques, like adeno-associated viruses (AAVs), in non-transgenic species. This study validates AAV tools for precise gene expression in pigeons. We identified AAV8 as a highly effective vector, demonstrating strong neuronal tropism and anterograde/retrograde transgene expression, while AAVretro was ineffective. The CaMKII promoter and mDLX enhancer enabled cell-type-specific expression, targeting predominantly excitatory and inhibitory neurons, respectively. Additionally, we established proof of concept for the expression of NpHR (a chloride pump) and demonstrated the functionality of conditional gene expression systems, including Cre/loxP and Tet-On/Tet-Off. These advancements expand the genetic toolkit for pigeons, facilitating precise manipulation of neural circuits and enabling future studies on complex avian behaviors and brain functions. By bridging molecular tools and avian neuroscience, this work paves the way for comparative and translational research, offering insights into the neural basis of cognition and sensory processing in birds.

neuroscience↗

bioRxiv2025

The Distribution of Nitric Oxide-Synthesizing Neurons and Soluble Guanylate Cyclase in the Pigeon Brain

Nitric oxide (NO) is a diffusible neuromodulator with roles in synaptic plasticity and memory flexibility, exerting its primary effects via the enzyme soluble guanylate cyclase (sGC). Despite its well-documented functions in mammals and insects, little is known about the neuroanatomical distribution and functional relevance of NO in birds, particularly in relation to dopaminergic systems. This study used histochemical and immunohistochemical techniques to map the distribution of NO-synthesizing neurons--identified by NADPH-diaphorase (NADPH-d) and nNOS activity--and their relation to sGC and tyrosine hydroxylase (TH)-positive dopaminergic pathways in the pigeon brain. We found extensive NADPH-d labeling throughout forebrain, midbrain, and hindbrain regions. Among TH-positive midbrain structures, the locus coeruleus exhibited high colocalization with nNOS, while moderate colocalization was seen in the ventral tegmental area substantia grisea centralis and substantia nigra. Notably, a significant proportion of sGC-positive neurons was targeted by TH and NADPH-d positive fibres in the pigeon NCL. Our findings support the potential for NO-dopamine interactions in avian species, reminiscent of memory-related mechanisms in Drosophila melanogaster, and contribute to an understanding of conserved pathways that may underlie flexible learning and memory processing during navigation or related tasks across vertebrates. This work also offers insight into comparative NADPH-d distribution among avian species, with implications for aging, spatial learning, and memory formation.

neuroscience↗

bioRxiv2020

Investigating real-life emotions in romantic couples: a mobile EEG study

The neural basis of emotional processing has been largely investigated in constrained spatial environments such as stationary EEGs or fMRI scanners using highly artificial stimuli like standardized pictures depicting emotional scenes. Typically, such standardized experiments have low ecological validity and it remains unclear whether their results reflect neuronal processing in real-life affective situations at all. Critically, emotional situations do not only encompass the perception of emotions, but also behavioral components associated with them. In this study, we aimed to investigate real-life emotions by recording couples in their homes using mobile EEG technology during embracing, kissing and emotional speech. We focused on asymmetries in affective processing as emotions have been demonstrated to be strongly lateralized in the brain. We found higher alpha and beta power asymmetry during kissing and embracing on frontal electrodes during emotional kisses and speech compared to a neutral control condition indicative of stronger left-hemispheric activation. In contrast, we found lower alpha power asymmetry at parieto-occipital electrode sites in the emotional compared to the neutral condition indicative of stronger right-hemispheric activation. Our findings are in line with models of emotional lateralization that postulate a valence-specific processing over frontal cortices and right-hemispheric dominance in emotional processing in parieto-occipital regions. Overall, we could thus support theories of emotional asymmetries which suggest that affective processing is not uniformly lateralized across the brain using a highly ecologically valid paradigm.

neuroscience↗