The Ancient Brainstem Reimagined: A Conserved Circuit for Selective Spatial Attention Opens a New Frontier in Cognitive Neuroscience
Uduak A. Inwang *
Department of Physiology, Faculty of Basic Medical Sciences,Alex Ekwueme Federal University, Ndufu Alike, Nigeria.
Daisy Dominic
Department of Nursing, Faculty of Nursing Sciences, Niger Delta University, Wilberforce Island, Amassoma, Bayelsa State, Nigeria.
Kubiat T. Umana
Department of Physiology, Faculty of Basic Medical Sciences, University of Uyo, Uyo, Nigeria.
Nze P. Odunnaya
Department of Physiology, Faculty of Basic Medical Sciences,Alex Ekwueme Federal University, Ndufu Alike, Nigeria.
Itoro L. Ikpe
Department of Human Physiology, Faculty of Basic Medical Sciences, Topfaith University, Mpatak, Akwa Ibom State, Nigeria.
Emmanuel O. Nwuzor
Department of Medical Biochemistry, Faculty of Basic Medical Sciences, David Umahi Federal University (DUFUHS), Uburu,Ebonyi State, Nigeria and International Institute for Infectious Diseases, Biosafety and Biosecurity Research, (DUFUHS), Uburu, Ebonyi State, Nigeria.
Emmanuel I. Obi
Department of Community Medicine, National Obstetric Fistula centre, Abakaliki, Nigeria and Department of Pharmacology, Faculty of Basic Clinical Sciences, Alex Ekwueme Federal University, Ndufu Alike, Nigeria.
Peter O. Odu
Department of Physiology, Faculty of Basic Medical Sciences,University of Calabar, Calabar, Cross River State, Nigeria.
Nwaigwe Chidera
Department of Medical Laboratory Sciences, Faculty of Allied and Health Sciences, Ekwueme Federal University, Ndufu Alike, Nigeria.
Bakumor S. Yolo
Department of Pharmacology, Faculty of Basic Medical Sciences, University of Calabar, Calabar, Nigeria.
Chibuzor O.Nworie
Department of Physiology, Faculty of Basic Medical Sciences,Alex Ekwueme Federal University, Ndufu Alike, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Selective spatial attention has commonly been studied through cortical networks, particularly the frontoparietal systems implicated in prioritising relevant sensory information. However, recent evidence from freely moving mice indicates that an evolutionarily ancient inhibitory brainstem population, termed parvocellular lateral tegmental inhibitory (PLTi) neurons, contributes critically to the selection of spatial targets. In a touchscreen-based attention task, bilateral PLTi silencing impaired target selection, particularly in the presence of competing distractors, while the reported control measures did not identify comparable impairments in visual perception or task-relevant movement. Neural recordings further suggested that PLTi activity influences representations of competing stimuli in the superior colliculus, potentially supporting the separation of behaviourally relevant targets from lower-priority distractors. These findings complement existing evidence that attentional selection involves interactions between cortical and subcortical circuits rather than exclusively cortical control. Comparative observations raise the possibility that some computational principles of attentional selection preceded the evolutionary expansion of the mammalian neocortex, although the degree of cellular conservation across vertebrates remains to be established. The potential relevance of this circuitry to attention-deficit/hyperactivity disorder, autism spectrum disorder and other neuropsychiatric conditions is considered as a hypothesis, not an established clinical mechanism. Direct evidence of corresponding human PLTi circuitry, disease involvement or treatment efficacy is currently lacking. Further comparative and translational investigations are required to clarify the circuit's contribution to human attention.
Keywords: Brainstem, cognitive neuroscience, evolutionarily conserved circuits, neuropsychiatry, selective attention, superior colliculus