Matrix Metalloproteinases Contribute to Neuronal Dysfunction in Animal Models of Drug Dependence, Alzheimer's Disease, and Epilepsy

Table 1

Summary of behavioral changes related to emotional responses in MMP-2^(−/−) and MMP-9^(−/−) mice.

Test	Parameters	MMP-9^(–/–)	MMP-2^(–/–)
Open-field test	Outer sector crossing	±	±
	Inner sector crossing	±	±
	Time in inner sector	±	±
	Number of rearing	⇑	±
	Number of grooming	±	±
	Start latency	⇓	⇓
Elevated plus-arm maze test	Time in open arm	⇑	±
	Open arm entries	⇑	±
	Time in closed arm	⇓	±
	Closed arm entries	±	±

Behavioral changes in MMP-9^(−/−) mice indicate that endogenous MMP-9 play a role in emotional behaviors.
±: no change; ⇑: significant increase versus wild-type mice; ⇓: significant decrease versus wild-type mice. Modified from Mizoguchi et al. [21].