Retinal Electrophysiology Is a Viable Preclinical Biomarker for Drug Penetrance into the Central Nervous System

Figure 3

Cortical electrophysiology following conscious isoguvacine/muscimol injections. VEP responses in animals ((a)–(d), for each drug group) at conscious baseline (black lines, average of vehicle injections in conscious groups) compared to (a) intramuscular and (b) intravitreal injection of isoguvacine (red) and (c) intramuscular and (d) intravitreal injection of muscimol (blue). (e)–(h) summarise VEP parameters (average ± SEM) following isoguvacine or muscimol injections via different routes (see method for details). Grey areas indicate 95% CI of the particular VEP parameter in all conscious baseline recordings. P1, P2, and N1 are marked in (a), with P2 taken as the first positive inflection following N1. .