5A. The recording sites and distribution of middle, central, and lateral zones are shown in Fig. 5B. The receptive fields recorded at 100-micron steps through the penetration are shown in the matrix format in Fig. 5C. In this example, the new input completely occupied the medial and lateral zones and encroached on the medial and lateral borders of the central zone. While this arrangement was most typical, 1 of the 5 rats had responsive sites distributed throughout the middle portion of the central zone. A total of 73 electrode penetrations (mean: 9.5 per animal)

BGJ398 was used to map CN at+300 μm to the obex in seven 4- and 5-WD rats; receptive fields were examined at 549 sites (mean: 79 per animal) at selleckchem +300 μm. A representative example is shown in Fig. 6 for one 5-WD rat. While the medial zone is completely occupied with new input, few sites

were responsive to new input in the central and lateral zones. The results for the forelimb-intact controls and deafferented groups are shown in the receptive field plots in Fig. 7. The receptive fields are partitioned into body, shoulder, and head/neck subdivisions, and each receptive field is plotted onto a standardized map of CN. Inspection of the map plots shows that even in the controls, receptive fields for each body part can be found in the medial and lateral zones. In the 1-WD rats, the central zone contains a few sites on the lateral border where shoulder and head/neck receptive fields were found. In the 2-WD rats, more sites were found in the central zone, but these were confined to the lateral edge. However in the 3-WD rats, many sites were observed in the central zone that received

input from each of the body parts; the medial and lateral zones also contained new receptive fields that were distributed throughout their zones. In contrast, the 4-WD and 5-WD rats had few examples of new input in the central zone and those that were seen were relegated to the medial and lateral borders. Interestingly, new inputs in the central zone in the 6–8-WD rats were only observed at the medial and lateral border regions, while 9–12-WD tuclazepam had a few new fields in the dorsal part of the central zone. The one 26-WD rat and one 30-WD rat also had new receptive fields localized to the medial and lateral borders of the central zone. The dataset for the total area (μm2 as measured at +300 μm anterior to the obex) of the cuneate nucleus; total areas of medial, central, and lateral zones; and total area of the new input from the body, shoulder, and head into each zone for both controls and forelimb deafferented rats is presented in Table 2. Inspection of Table 2 shows the existence of a great deal of variability in body part maps among individual members within an experimental group, and the data were often skewed by one individual.