What Sensory Signals are About

Kathleen Akins argues that "the traditional view" of sensory systems assumes too quickly that their function is detecting features of the outside environment. Instead, some systems are "narcissistic"--their signals tell their own states--and others may send signals that are not about anything at all. But Akins overlooks that "traditionalists" may argue, with Millikan, that the function of sensory systems may be steering motor routines. Aboutness comes in as how the systems have steered in ways evolution liked--by gearing steering to external features. Color vision and olfaction, for example, are thus, about external features.

Potential Role of Adenosine Signaling in Acetic Acid Activation of Murine Sensory Neurons

Chronic respiratory illnesses are a significant cause of morbidity and mortality, and acute changes in respiratory function often lead to hospitalization. Air pollution is known to exacerbate asthma, but the molecular mechanisms of this are poorly understood. The current studies were aimed at clarifying the roles of nerve subtypes and purinergic receptors in respiratory reflex responses following exposure to irritants. In C57Bl/6J female mice, inspired adenosine produced sensory irritation, shown to be mediated mostly by A-delta fibers. Secondly, the response to inhaled acetic acid was discovered to be dually influenced by C and A-delta fibers, as indicated by the observed effects of capsaicin pretreatment, which selectively destroys TRPV1-expressing fibers (mostly C fibers) and pretreatment with theophylline, a nonselective adenosine receptor antagonist. The responses to both adenosine and acetic acid were enhanced in the ovalbumin-allergic airway disease model, although the particular pathway altered is still unknown.