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Updated: Mar 5, 2026
Neurodevelopmental Reflex Testing in Neonatal Rat Pups
Published on: April 24, 2017
Neonatal reflexes and behavior in hypertensive rats of ISIAH strain
Diana S Ragaeva1, Maria A Tikhonova2, Olga M Petrova3
1Federal State Budgetary Scientific Institution "Federal Research Center Institute of Cytology and Genetics", Novosibirsk 630090, Russia.
Insights
Inherited stress-induced arterial hypertension (ISIAH) rats show accelerated neurodevelopment and increased activity in adulthood. These hypertensive rats exhibit advanced reflexes and higher hippocampal neuronal density compared to normotensive controls.
Area of Science:
- Neuroscience
- Cardiovascular Science
- Developmental Biology
Background:
- Hypertension is a prevalent human disease with potential impacts on newborns.
- The inherited stress-induced arterial hypertension (ISIAH) rat model offers a unique opportunity to study hypertension-related neurodevelopmental and behavioral changes.
- Limited research exists on the behavioral aspects of ISIAH rats.
Purpose of the Study:
- To compare neurodevelopmental markers, hippocampal neuronal density, and adult behavior in ISIAH rats versus normotensive WAG rats.
- To investigate the long-term consequences of ISIAH on physical growth, blood pressure, and anxiety-related behaviors.
Main Methods:
- Comparative analysis of body weight, neurodevelopmental reflexes (e.g., grasp reflex, negative geotaxis), and hippocampal neuronal density (CA1, CA3) in ISIAH and WAG pups.
- Assessment of adult ISIAH and WAG rats (12-14 weeks old) using behavioral tests: Open Field (OF), Elevated Plus Maze (EPM), and Novel Object Recognition (NOR).
- Measurement of systolic and diastolic blood pressure (SBP, DBP) in adult rats.
Main Results:
- ISIAH pups exhibited advanced neurodevelopmental reflexes and higher hippocampal neuronal density compared to WAG pups.
- Adult ISIAH rats were heavier, with elevated SBP and DBP, and displayed increased locomotor and exploratory activity in OF and EPM tests.
- ISIAH rats showed reduced anxiety levels and similar recognition memory but higher exploratory drive in the NOR test compared to WAG rats.
Conclusions:
- Hypertensive ISIAH rats demonstrate accelerated neurodevelopment during the suckling period.
- Adult ISIAH rats are characterized by increased physical activity, lower anxiety, and enhanced exploratory behavior compared to normotensive WAG rats.
- These findings highlight a potential link between hypertension, accelerated development, and distinct behavioral phenotypes in the ISIAH rat model.
Abstract:
Hypertension is one of the most common diseases in humans, and there is a special concern on the consequences of maternal hypertensive conditions for the health of newborns. An inherited stress-induced arterial hypertension (ISIAH) rat strain has been selected but only a few studies have addressed behavior in these rats. Body weight, neurodevelopmental reflexes, and neuronal density in the hippocampus were compared in ISIAH and normotensive WAG rats during their suckling period. Systolic and diastolic blood pressure (SBP, DBP), adult rat performance in the open field (OF), elevated plus maze (EPM), and novel object recognition (NOR) tests were evaluated at the age of 12-14weeks old. Body weight in pups did not differ significantly during the suckling period, while adult ISIAH rats were heavier than age-matched WAG rats and possessed the increased SBP and DBP. ISIAH pups were developmentally more advanced than WAG as indicated by grasp reflex and negative geotaxis reaction scores. This was associated with higher neuronal density in CA1 and CA3 hippocampal areas in ISIAH pups on postnatal day 6 as compared to WAG rats. Adult ISIAH rats demonstrated an increased locomotor and exploratory activity in the OF and EPM tests as well as low levels of anxiety. The NOR test revealed no significant difference in recognition but confirmed higher exploratory activity in ISIAH rats compared to WAG rats. The results indicate that hypertensive ISIAH rats feature accelerated development during their suckling period, and as adults, they are more active and less anxious than normotensive WAG rats.
