Fig. 3

Recording sites. a An exemplary photomicrograph of a wet unstained thalamic section showing the method for localization. Two electrolytic lesions (asterisk), separated by 1 mm, were made in the recording track. Sixteen equally spaced recording sites were identified by interpolation. The subnuclei were confirmed with acetylcholinesterase staining. Scale bar: 1 mm. b–d Distribution of the recording sites in all rats is shown on coronal diagrams of the medial thalamus in a standard atlas [24], 2.8 (b), 3.3 (c), and 3.6 (d) mm caudal to the bregma. Eight categories of units were identified: open circles, pinch excitatory; open squares, heat excitatory; open triangles, pinch and heat excitatory; solid circles, pinch inhibitory; solid squares, heat inhibitory; solid triangles, pinch and heat inhibitory; dashes, units responding to neither stimuli; and slash, mix responsive. Scale bar of (b–d): 0.5 mm