# \#variables **URL:** https://brian.discourse.group/tag/variables/64.md [Latest](https://brian.discourse.group/latest.md) · [Categories](https://brian.discourse.group/categories.md) · [Tags](https://brian.discourse.group/tags.md) --- ## [Equation constants that do not change between runs](https://brian.discourse.group/t/equation-constants-that-do-not-change-between-runs/1253)
**Author:** [@bjourne](https://brian.discourse.group/u/bjourne)\ **Replies:** 3\ **Last updated:** [11 July 2024 15:51 UTC](https://brian.discourse.group/t/equation-constants-that-do-not-change-between-runs/1253 "2024-07-11T15:51:20Z")
I accidentally discovered that Brian2 treats eqs = '''dv/dt = (v\_rest - v + i\_exc + i\_inh) / (100\*ms) : volt (unless refractory)''' and tau\_m = 100 \* ms eqs = '''dv/dt = (v\_rest - v + i\_exc + i\_inh) / tau\_m : volt (u…