Hindmarsh JL, Rose RM (1984) A model of neuronal bursting using three coupled first order differential equations. Proc R Soc Lond B Biol Sci 221:87-102
doi: 10.1098/rspb.1984.0024

The model is available at the Brian 2 website where it can be run and edited without installing any software (in a Binder service):

https://brian2.readthedocs.io/en/stable/examples/frompapers.Hindmarsh_Rose_1984.html