Trigeminal sensorimotor mechanisms and eating in the rat

Area of Science:

• Neuroscience
• Sensory Physiology
• Animal Behavior

Background:

• Eating is a complex behavior involving sensory feedback.
• The trigeminal nerve plays a role in orofacial sensation and motor control.

Purpose of the Study:

• To investigate the role of trigeminal inputs in the behavioral organization of eating in rats.
• To determine if orosensory information is necessary for proper jaw movement during feeding.

Main Methods:

• Photographic, electrophysiological, and neurobehavioral analyses were employed.
• Trigeminal orosensory deafferentation was performed, sparing jaw muscle afferents and efferents.
• Stimulation of oral and perioral areas was used to assess neural responses.

Main Results:

• Jaw opening during eating was consistently preceded by perioral contact.
• Electrical or mechanical stimulation of oral/perioral areas evoked responses in the mylohyoid nerve.
• Trigeminal deafferentation abolished or significantly reduced mouth opening during eating.

Conclusions:

• Trigeminal orosensory inputs are essential for mediating eating behavior in rats.
• These inputs form a critical link in the stimulus-response chain for feeding.
• Orosensory feedback is vital for the motor control of jaw movements during ingestion.