Subarachnoid hemorrhage leads to early and persistent functional connectivity and behavioral changes in mice

J Cereb Blood Flow Metab. 2021 May;41(5):975-985. doi: 10.1177/0271678X20940152. Epub 2020 Sep 16.


Aneurysmal subarachnoid hemorrhage (SAH) leads to significant long-term cognitive deficits, which can be associated with alterations in resting state functional connectivity (RSFC). However, modalities such as fMRI-which is commonly used to assess RSFC in humans-have practical limitations in small animals. Therefore, we used non-invasive optical intrinsic signal imaging to determine the effect of SAH on RSFC in mice up to three months after prechiasmatic blood injection. We assessed Morris water maze (MWM), open field test (OFT), Y-maze, and rotarod performance from approximately two weeks to three months after SAH. Compared to sham, we found that SAH reduced motor, retrosplenial, and visual seed-based connectivity indices. These deficits persisted in retrosplenial and visual cortex seeds at three months. Seed-to-seed analysis confirmed early attenuation of correlation coefficients in SAH mice, which persisted in predominantly posterior network connections at later time points. Seed-independent global and interhemispheric indices of connectivity revealed decreased correlations following SAH for at least one month. SAH led to MWM hidden platform and OFT deficits at two weeks, and Y-maze deficits for at least three months, without altering rotarod performance. In conclusion, experimental SAH leads to early and persistent alterations both in hemodynamically derived measures of RSFC and in cognitive performance.

Keywords: Subarachnoid hemorrhage; cerebral aneurysm; delayed cerebral ischemia; functional connectivity; mild cognitive impairment.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Behavior, Animal / physiology
  • Brain Ischemia / diagnostic imaging*
  • Brain Ischemia / metabolism
  • Brain Ischemia / physiopathology
  • Case-Control Studies
  • Cognitive Dysfunction / diagnosis
  • Cognitive Dysfunction / etiology
  • Cognitive Dysfunction / physiopathology*
  • Disease Models, Animal
  • Magnetic Resonance Imaging / methods*
  • Male
  • Maze Learning / physiology
  • Mice
  • Mice, Inbred C57BL
  • Neurovascular Coupling / physiology
  • Open Field Test / physiology
  • Rotarod Performance Test / methods
  • Subarachnoid Hemorrhage / complications
  • Subarachnoid Hemorrhage / physiopathology*
  • Visual Cortex / metabolism
  • Visual Cortex / physiopathology*