Aim: Ferulic acid (4-hydroxy-3-methoxycinnamic acid, FA) provides neuroprotection against apoptosis in a transient middle cerebral artery occlusion (MCAo) model. This study was to further investigate the anti-apoptotic effect of FA during reperfusion after cerebral ischemia. Methods: Rats were subjected to 90 min of cerebral ischemia followed by 3 or 24 h of reperfusion after which they were sacrificed. Results: Intravenous FA (100 mg/kg) administered immediately after middle cerebral artery occlusion (MCAo) or 2 h after reperfusion effectively abrogated the elevation of postsynaptic density-95 (PSD-95), neuronal nitric oxide synthase (nNOS), inducible nitric oxide synthase (iNOS), nitrotyrosine, and cleaved caspase-3 levels as well as apoptosis in the ischemic cortex at 24 h of reperfusion. FA further inhibited Bax translocation, cytochrome c release, and p38 mitogen-activated protein (MAP) kinase phosphorylation. Moreover, FA enhanced the expression of gamma-aminobutyric acid type B receptor subunit 1 (GABA B1 ) in the ischemic cortex at 3 and 24 h of reperfusion. In addition, nitrotyrosine-positive cells colocalized with cleaved caspase-3-positive cells, and phospho-p38 MAP kinasepositive cells colocalized with nitrotyrosine-and Bax-positive cells, indicating a positive relationship among the expression of nitrotyrosine, phospho-p38 MAP kinase, Bax, and cleaved caspase-3. The mutually exclusive expression of GABA B1 and nitrotyrosine revealed that there is a negative correlation between GABA B1 and nitrotyrosine expression profiles. Additionally, pretreatment with saclofen, a GABA B receptor antagonist, abolished the neuroprotection of FA against nitric oxide (NO)-induced apoptosis. Conclusion: FA significantly enhances GABA B1 receptor expression at early reperfusion and thereby provides neuroprotection against p38 MAP kinase-mediated NO-induced apoptosis at 24 h of reperfusion.Keywords: ferulic acid; neuronal nitric oxide synthase; inducible nitric oxide synthase; Bax; p38 mitogen-activated protein kinase; nitric oxide-induced apoptosis