Table 4. Parameter estimates for the linear mixed effect (LME) models used to assess changes in axon-spine interfaces (ASI).

A square-root transformation was applied to the ASI values to ensure the residuals had an approximate Gaussian distribution. Residual analysis showed only minor departures from normality and constant variance in the ASI models, and no evidence against the assumptions in the cumulative ASI model.

ASI − sqrt(ASI)
Random effects	Standard error
Dendrite (intercept)	0.0134
Mouse (intercept)	0.0164
Residual	0.1219
Fixed effects	Level	Estimate	Standard error
Intercept		0.3797	0.0227
Dendrite diameter	Continuous (linear)	–1e-7	2e-5
Condition	EW (reference)	0	0
	W	0.0331	0.0129
	S	0.0197	0.0118
ASI (with branched) – sqrt(ASI)
Random effects	Standard error
Dendrite (intercept)	0.0132
Mouse (intercept)	0.0168
Residual	0.1217
Fixed effects	Level	Estimate	Standard error
Intercept		0.3812	0.0227
Dendrite diameter	Continuous (linear)	7e-7	2e-5
Condition	EW (reference)	0	0
	W	0.0333	0.0132
	S	0.0184	0.0120
Branched	No (reference)	0	0
	Yes	–0.0217	0.0052
ASI density (sum ASI/surface area)
Random effects	Standard error
Mouse (intercept)	0.0425
Residual	0.0608
Fixed effects	Level	Estimate	Standard error
Intercept		0.3159	0.0247
Condition	EW (reference)	0	0
	W	–0.0042	0.0349
	S	–0.0131	0.0316