Properties of tactile responses of neurons in rat thalamic ventroposterolateral nucleus

Objective: To determine whether the convergences of tactile information also occur at thalamic ventroposterolateral nucleus in rats, we investigated the properties of tactile responses of the thalamic ventroposterolateral nucleus in rats. Methods: Unit responses were recorded extracellularly from thalamic ventroposterolateral nucleus in anesthetized rats. Results: Among 156 neurons examined, 140 neurons (89.7%) had the single, continual and small receptive fields, and 16 neurons (10.3%) had two discrete receptive fields. Some neurons exhibited different responses to the same intensity stimulation which delivered to different points in their receptive fields. In addition, 4.5% neurons (n = 7) responded only to locomotive stimulation but not to a punctiform tactile stimulation. Conclusion: The majority of neurons in ventroposterolateral nucleus of rats have the spatial, temporal and submodal characteristics of cutaneous receptors, while the minority of neurons exhibit the responses of interaction of different peripheral receptors. Therefore, it is concluded that there are convergences of tactile information at the ventroposterolateral nucleus of rats.