The disclosure relates to pentylenetetrazole (PTZ) derivates having formula (l) wherein R1 &ndash R10 are independently selected from hydrogen and deuterium, wherein at least one is not hydrogen, or a pharmaceutically salt thereof. The disclosure also relates to pharmaceutical compositions comprising these compounds and their use in the increasing blood flow, heart rate or breathing rate in an individual The disclosure also relates to their use for treating senility, senile confusion, psychoses, psychoneuroses when anxiety and nervous tension were present, cerebral arteriosclerosis, nausea, depression, fatigue, debilitation, mild behavioral disorders, irritability, emotional instability, antisocial attitudes, anxiety, vertigo or incontinence, or symptom thereof, or in improving cognitive function in individuals, for instance, in individuals with Down syndrome and other conditions. Example compounds include: 6,6,8,8,10,10-d6-6,7,8,9-tetrahydro-5Htetrazolo[1,5-a]-azepine
