Physiological gating of chemosensory processing: a receiver-state model with cross-species implications.

Neurobiological evidence indicates that sensory processing is dynamically shaped by the physiological state of the organism. In chemical communication, stimulus effectiveness depends on ligand-receptor interactions together with environmental transport, sensory access, and endocrine, autonomic, vascular and neural conditions that regulate stimulus availability and system responsiveness. This review develops physiological gating as a receiver-state model of chemosensory effectiveness. Physiological gating describes coordinated regulation across three interacting levels: stimulus access and receptor detection, neural integration, and organismal physiological state. The model synthesises evidence from olfactory neurobiology, sensory physiology, neuroendocrinology and behavioural neuroscience to explain why identical chemical cues may elicit different behavioural or physiological outcomes depending on reproductive state, developmental stage, metabolic condition, previous experience and environmental context. Building on established receiver-state effects, the original contribution of this model is to integrate peripheral stimulus availability with vascular, endocrine, autonomic and neural regulation in a single testable account. Vascular regulation is proposed as a candidate active component and is supported most directly by studies of isolated superficial nasal and facial veins in swine; its causal effects on odorant access and its broader relevance across species remain to be tested. The review also considers olfactory valence, multimodal integration and dog-human interactions as examples of how chemical cues may influence behaviour through compatibility between sensory systems and physiological regulatory states. Finally, we outline experimentally testable predictions and component-specific criteria that could constrain or challenge physiological gating.