Fig. 2

Effects of hNB001 on recent or remote auditory fear memory in adult or aged mice. a Schematic diagram showing auditory fear memory performed on mice. The CS is a tone (2800 Hz, 85 dB, 30 s). The US is a foot shock (0.75 mA, 2 s) that co-terminated with the tone. Mice were conditioned by three CS/US pairings at 30 s intervals for training. 45 min after oral administration of hNB001 (10 mg/kg) or saline, mice received 3 CS–ITI trials in a novel chamber for recent fear memory test after one day of training (Test 1). The mice were given hNB001 orally twice a day for 30 days. Remote fear memory test was performed again 30 days later (Test 2). b There was no significant difference in the recent fear memory between adult and aged mice, but remote fear memory of aged mice was significantly impaired compared with adult mice (Recent, saline, n = 10 mice, hNB001, n = 10 mice, Student’s t-test, t ₍₁₈₎ = 1.594, p = 0.1283; Remote, saline, n = 7 mice, hNB001, n = 8 mice, Student’s t-test, t ₍₁₃₎ = 4.221, p = 0.0010). c Oral administration of hNB001 for a single or 30 days did not affect recent (left) or remote (right) auditory fear memory in adult mice (Recent, saline, n = 10 mice, hNB001, n = 10 mice, Student’s t-test, t ₍₁₈₎ = 0.2439, p = 0.8101; Remote, saline, n = 7 mice, hNB001, n = 10 mice, Student’s t-test, t ₍₁₅₎ = 0.9273, p = 0.3685). d Oral administration of hNB001 for a single or 30 days did not affect recent (left) or remote (right) auditory fear memory in aged mice (Recent, saline, n = 9 mice, hNB001, n = 10 mice, Student’s t-test, t ₍₁₇₎ = 0.6973, p = 0.4950; Remote, saline, n = 8 mice, hNB001, n = 10 mice, Student’s t-test, t ₍₁₆₎ = 1.296, p = 0.2133). ***p < 0.001