What are vlasoyedy in rats? - briefly
Vlasoyedy denotes the tendency of rats to gnash and swallow their own hair, creating ingested fur masses. These hair accumulations can form trichobezoars that obstruct the gastrointestinal tract, leading to decreased food intake and weight loss.
What are vlasoyedy in rats? - in detail
Vlasoyedy, also known as whisker‑feeding structures, refer to the specialized oral‑facial apparatus in rodents that integrates the vibrissal system with the feeding mechanism. The term describes the anatomical configuration where the mystacial vibrissae are positioned to contact food items during ingestion, providing tactile feedback that guides mandibular movements.
The apparatus consists of:
- Mystacial vibrissae: long, highly innervated hairs emerging from the rostral facial region.
- Innervation: trigeminal nerve branches supply sensory fibers, while facial motor nuclei control the intrinsic muscles that adjust whisker orientation.
- Musculature: small orbicularis oris and buccinator fibers coordinate whisker positioning with jaw closure.
- Skeletal support: enlarged infraorbital foramen and modified maxillary bone accommodate increased nerve and vascular bundles.
Functionally, vlasoyedy enable precise detection of food texture, size, and location, especially under low‑light conditions. The tactile input modulates central pattern generators in the brainstem, synchronizing bite force and chewing rhythm. Electrophysiological recordings show that whisker deflection during feeding generates spike trains in the ventral posteromedial thalamus, which are relayed to the somatosensory cortex, influencing decision‑making about mastication.
Occurrence is documented in several rat species, including Rattus norvegicus and Rattus rattus. Comparative studies reveal that laboratory strains exhibit a more pronounced whisker‑feeding coupling than wild counterparts, likely due to selective breeding for enhanced sensory acuity.
Research methods for examining this system include:
- High‑speed videography: captures whisker‑food contact dynamics at millisecond resolution.
- Micro‑CT imaging: visualizes bone remodeling around the infraorbital region.
- In vivo electrophysiology: records neuronal activity in trigeminal nuclei during feeding bouts.
- Behavioral assays: assess performance on textured food discrimination tasks.
Pathological alterations, such as vibrissal loss or infraorbital nerve damage, impair feeding efficiency, leading to reduced body weight and altered gnawing patterns. Restoration of whisker function through prosthetic vibrissae restores normal mastication metrics in experimental models.
Overall, the vlasoyedy system represents a tightly integrated sensory‑motor network that enhances feeding precision in rats, providing a valuable model for studying somatosensory contributions to oral behavior.