TABLE 1

Desensitization rates for mutant GluR6 subunits

Values are given as mean ± S.E.M. for n determinations. For double exponential fits, the contribution of the fast component is indicated as a percentage in brackets.

Mutant	Glu							KA
Mutant		I_peak	τ_Des	des	n	I_KA/Glu	τ_Des	des	n	I_Dom/Glu	τ_Des	des	n
	nA	ms	%			ms	%			ms	%
WT	6.2 ± 0.4	5.3 ± 0.2	99.4 ± 0.2	27	0.70 ± 0.05	4.1 ± 0.3	99.4 ± 0.1	13	0.39 ± 0.04	τ₁ = 26 ± 1.1	83.8 ± 1.5	23
										(97 ± 0.4%)
										τ₂ = 550 ± 95
A490M	5.9 ± 1.8	3.6 ± 0.1	98.9 ± 0.4	5	0.94 ± 0.04^*	5.3 ± 0.3	97.8 ± 0.9	5	0.68 ± 0.08^*	τ₁ = 26 ± 0.5	77.4 ± 4.2	5
										(96 ± 1.4%)
										τ₂ = 250 ± 45
A490R	3.2 ± 1.2	3.6 ± 0.6	99.7 ± 0.1	4	1.5 ± 0.2^*	3.4 ± 0.4	99.6 ± 0.2	3	0.98 ± 0.07^*	τ₁ = 21 ± 2.5	87.8 ± 2.4	5
										(97 ± 0.9%)
										τ₂ = 190 ± 30
V685E	0.58 ± 0.25^a	5.7 ± 0.6	99.9 ± 0.1	4	N.D.^b	N.D.	98.5 ± 1.5	4	N.R.			4
V685K	1.9 ± 0.5^a	4.2 ± 0.6	98.4 ± 0.9	3	N.D.^b	5.3 ± 0.3	99.1 ± 0.7	12	N.R.			8
V685Q	6.0 ± 0.6	4.5 ± 0.2	99.4 ± 0.2	17	0.73 ± 0.03	4.7 ± 0.3	99.0 ± 0.2	13	0.24 ± 0.03^*	τ₁ = 50 ± 3.0	82.4 ± 1.8	17
										(95 ± 0.7%)
										τ₂ = 1100 ± 300
M691A	4.4 ± 1.9	4.4 ± 0.6	99.8 ± 0.03	4	0.45^* ± 0.1	3.6 ± 0.5	99.9 ± 0.1	4	0.18 ± 0.04^*	τ₁ = 15 ± 2.1	95.4 ± 1.5^*	4
										(95 ± 1.7%)
										τ₂ = 450 ± 170
M691K	7.2 ± 1.3	5.6 ± 0.6	99.6 ± 0.2	5	0.54 ± 0.07	4.8 ± 0.6	98.5 ± 1.0	4	0.24 ± 0.05	τ₁ = 13 ± 0.9	94.3 ± 1.5^*	4
										(95 ± 2.6%)
										τ₂ = 230 ± 55

N.D., not determined; N.R., no response.
↵* P < 0.05, unpaired t-test compared to GluR6 WT.
↵ a Glu concentration was 10 mM.
↵ b Mean peak responses to 100 μM KA were 0.06 ± 0.04 and 0.3 ± 0.09 nA, respectively.