What are the whiskers of rats called? - briefly
Rats’ whiskers are called vibrissae, a type of specialized tactile hair. They function as sensory organs that detect environmental cues.
What are the whiskers of rats called? - in detail
Rat whiskers are referred to as vibrissae, specialized tactile hairs located primarily on the snout, but also on the cheeks, above the eyes, and on the forelimbs. Each vibrissa consists of a thick, keratinized shaft emerging from a deep follicle that contains a rich network of mechanoreceptors. The follicle is supplied by the trigeminal nerve, which transmits deflection signals to the somatosensory cortex, enabling precise spatial awareness.
The vibrissal system is divided into two functional groups:
- Macrovibrissae – long hairs arranged in a grid on the rostral face; length varies from 5 mm to over 30 mm; each hair is individually movable and provides coarse positional data.
- Microvibrissae – short hairs surrounding the eyes and lips; length typically below 2 mm; they detect fine surface textures and airflow.
Key anatomical features include:
- A sinusoidal blood sinus surrounding the follicle, which amplifies mechanical stimuli.
- A dense capsule of Merkel cells, lanceolate endings, and Ruffini endings that encode direction, velocity, and force of whisker movement.
- A muscular ring (intrinsic musculature) that adjusts whisker angle, allowing active whisking at frequencies up to 12 Hz.
During development, vibrissae appear in the embryonic stage around day 13 of gestation and continue to grow throughout the animal’s life, shedding periodically in a cycle of approximately 30 days. Genetic factors such as the Eda and Fgf pathways regulate follicle formation, while sensory experience influences cortical representation.
Comparative studies show that rat vibrissae share structural similarity with those of other rodents, yet differ in density and length, reflecting ecological adaptations. In laboratory settings, vibrissal tracking provides a reliable metric for assessing sensorimotor function, pain perception, and neurological disease models.