Table 1.

Buffer and nerve terminal properties

Terminals	Kd,e1	BT,e1	Kd,e2	BT,e2	VA	[Ca2+]Free,0	n
	µM	µM	µM	µM		µM
One buffer	1.5 ± 0.2	170 ± 46	-	-	0.52 ± 0.10	0.607 ± 0.13	8
Two buffer	0.38 ± 0.08	340 ± 110	4.7 ± 0.8	140 ± 40	0.38 ± 0.05	0.570 ± 0.09	9

Properties of endogenous Ca²⁺ buffers in nerve terminals with one or two species. K_d and B_T are the dissociation constant and total concentration of endogenous buffers, respectively (Eq. 2). V_A is the fraction of total cellular volume accessible to Ca²⁺; [Ca²⁺]_Free,0 is the resting Ca²⁺ concentration computed from resting F with Eq. 1.