Table 1.

Frequency of filopodia, perforated spines, spinules, stubby spines, and branched spines in different brain regions

Brain region	Filopodia (%)	Perforated spines (%)	Spinules (%)	Stubby spines (%)	Branched spines (%)	Number of spines in branches (range)
CA1 PSR	1.78	2.72	3.26	2.90	7.97	2
CA1 SLM	0.00	50.00	8.57	1.43	0.00	– –
Cortex	3.07	8.60	0.90	2.26	9.50	2–4
Striatum	5.84	4.47	4.71	0.00	13.40	2–3
CB	4.19	0.00	0.61	0.00	12.62	2–5

Filopodia lack synaptic contacts with the presynaptic terminals.