Table 2.

Alterations in the morphology and apposition of nerve terminals (NTs) and terminal SCs (TSCs) resulting from GGF2 treatment from P11 to P12 or P13

	Column 1 No. of endplates observed (% of all endplates)	Column 2 No. of endplates in column 1 with altered TSCS (% of column 1)	Types of TSC changes observed		Column 5 NT sprout, no. (% of column 2)
			Column 3 Only TSC process extension, no. (% of column 2)	Column 4 TSC position or coverage altered,2-ano. (% of column 2)
Control (four muscles, 87 endplates)
NTs precisely overlie AChR plaque	78  (90)	14  (18)	10  (71)	4  (29)	5  (36)
NTs with decreased synaptophysin density	3  (3)	0  (0)	0  (0)	0  (0)	0  (0)
NTs fail to cover entire AChR plaque	6  (7)	1  (17)	0  (0)	1  (100)	0  (0)
GGF2 P11–P12 (three muscles, 59 endplates)
NTs precisely overlie AChR plaque	51  (86)	12  (24)	8  (67)	4  (33)	2  (17)
NTs with decreased synaptophysin density	7  (12)	3  (43)	3  (100)	0  (0)	2  (67)
NTs fail to cover entire AChR plaque	1  (2)	1  (100)2-b	0  (0)	1  (100)	1  (100)
GGF2 P11–P13 (four muscles, 124 endplates)
NTs precisely overlie AChR plaque	57  (46)	39  (68)	10  (26)	29  (74)	10  (26)
NTs with decreased synaptophysin density	46  (37)	38  (83)	11  (29)	27  (71)	17  (45)
NTs fail to cover entire AChR plaque	21  (17)	20  (95)	3  (15)	17  (85)	6  (30)

^F2-a The apposition of TSCs and NTs was judged to be altered if SC bodies had migrated off of endplates and if regions of the AChR plaque were not covered or were covered by only a thin veil of SC membrane. All NT sprouts were observed to be associated with processes of the TSC.

^F2-b This one observation of a nerve terminal that failed to cover the entire endplate may not accurately assess the frequency of occurrences of this type, because only 59 endplates were analyzed; however, 1 d later there are large numbers of endplates of this type, suggesting this is a real consequence of GGF2 treatment.