Changes in neurotransmitter metabolism following olfactory bulbectomy in the rat

Medium- and high-intensity rTMS reduces psychomotor agitation with distinct neurobiologic mechanisms

“…Our IPA identified glutamate degradation, glutamate-dependent acid resistance, GABA receptor signaling, and 4-aminobutryate degradation as systems that were both downregulated following OB surgery and upregulated by HI-rTMS and, to a lesser extent, MI-rTMS. Consistent with our findings, changes in GABAergic and glutamatergic processes in the brain have been reported following OB 59 – 62 and in the brain and blood of depressed patients 63 . Furthermore, rTMS in rodents and in humans can selectively alter GABA and glutamate levels in the brain and blood 64 – 66 .…”

Medium- and high-intensity rTMS reduces psychomotor agitation with distinct neurobiologic mechanisms

“…Our IPA identified glutamate degradation, glutamate-dependent acid resistance, GABA receptor signaling, and 4-aminobutryate degradation as systems that were both downregulated following OB surgery and upregulated by HI-rTMS and, to a lesser extent, MI-rTMS. Consistent with our findings, changes in GABAergic and glutamatergic processes in the brain have been reported following OB 59 – 62 and in the brain and blood of depressed patients 63 . Furthermore, rTMS in rodents and in humans can selectively alter GABA and glutamate levels in the brain and blood 64 – 66 .…”

Fish oil improves anxiety‐like, depressive‐like and cognitive behaviors in olfactory bulbectomised rats

“…The antidepressant effect of FO has been attributed to its ability to increase hippocampal BDNF and 5‐HT levels (Venna et al ., ; Vines et al ., ). In fact, the neurochemical data showed that hippocampal levels of 5‐HT and 5‐HIAA, but not 5‐HT turnover, were decreased by Obx, replicating previous studies (Jancsar & Leonard, ; Moriguchi et al ., ; Song & Wang, ). Importantly, FO supplementation in Obx rats reversed the 5‐HT hippocampal deficit induced by the lesion.…”

Neurokinin-1 receptor deletion modulates behavioural and neurochemical alterations in an animal model of depression

“…It should be noted that towards the end of the trial, locomotor activity of OB NK1−/− mice returns to that of wild type counterparts, indicating that, although the substance P/NK1 receptor system may be involved in the initial reactivity of OB mice to a novel stressor, other transmitter systems are likely to also be involved in the altered behavioural responding in the model. Alterations in monoaminergic neurotransmission have been the most widely studied neurochemical change examined in the OB model, with reduced serotonin and noradrenaline functioning (typically measured as steady state neurotransmitter levels) observed in discrete brain regions such as the frontal cortex, amygdala, hippocampus and midbrain [42,62,[80][81][82][83][84][85]. In accordance with these findings, the present study demonstrated that the serotonin metabolite 5HIAA and noradrenaline levels were significantly reduced in the frontal cortex of OB mice.…”

“…In comparison, serotonin levels in the amygdala were increased in OB mice when compared to Sham-operated wild type controls. Methodological differences such as strain/species of animal used, time post surgery, time post behavioural testing and technique used may account for the discrepancy between our finding and those previously reporting reduced serotonin functioning in the amygdala of OB animals [62,82,83]. Chronic antidepressant treatment has been demonstrated to normalise not only many of the behavioural but also the neurochemical changes observed following bulbectomy [for review see [36,37]].…”

Medium- and high-intensity rTMS reduces psychomotor agitation with distinct neurobiologic mechanisms

“…Our IPA identified glutamate degradation, glutamate-dependent acid resistance, GABA receptor signaling, and 4-aminobutryate degradation as systems that were both downregulated following OB surgery and upregulated by HI-rTMS and, to a lesser extent, MI-rTMS. Consistent with our findings, changes in GABAergic and glutamatergic processes in the brain have been reported following OB 59 – 62 and in the brain and blood of depressed patients 63 . Furthermore, rTMS in rodents and in humans can selectively alter GABA and glutamate levels in the brain and blood 64 – 66 .…”

Fish oil improves anxiety‐like, depressive‐like and cognitive behaviors in olfactory bulbectomised rats

“…The antidepressant effect of FO has been attributed to its ability to increase hippocampal BDNF and 5‐HT levels (Venna et al ., ; Vines et al ., ). In fact, the neurochemical data showed that hippocampal levels of 5‐HT and 5‐HIAA, but not 5‐HT turnover, were decreased by Obx, replicating previous studies (Jancsar & Leonard, ; Moriguchi et al ., ; Song & Wang, ). Importantly, FO supplementation in Obx rats reversed the 5‐HT hippocampal deficit induced by the lesion.…”

Neurokinin-1 receptor deletion modulates behavioural and neurochemical alterations in an animal model of depression

“…It should be noted that towards the end of the trial, locomotor activity of OB NK1−/− mice returns to that of wild type counterparts, indicating that, although the substance P/NK1 receptor system may be involved in the initial reactivity of OB mice to a novel stressor, other transmitter systems are likely to also be involved in the altered behavioural responding in the model. Alterations in monoaminergic neurotransmission have been the most widely studied neurochemical change examined in the OB model, with reduced serotonin and noradrenaline functioning (typically measured as steady state neurotransmitter levels) observed in discrete brain regions such as the frontal cortex, amygdala, hippocampus and midbrain [42,62,[80][81][82][83][84][85]. In accordance with these findings, the present study demonstrated that the serotonin metabolite 5HIAA and noradrenaline levels were significantly reduced in the frontal cortex of OB mice.…”

“…In comparison, serotonin levels in the amygdala were increased in OB mice when compared to Sham-operated wild type controls. Methodological differences such as strain/species of animal used, time post surgery, time post behavioural testing and technique used may account for the discrepancy between our finding and those previously reporting reduced serotonin functioning in the amygdala of OB animals [62,82,83]. Chronic antidepressant treatment has been demonstrated to normalise not only many of the behavioural but also the neurochemical changes observed following bulbectomy [for review see [36,37]].…”

Medium- and high-intensity rTMS reduces psychomotor agitation with distinct neurobiologic mechanisms

“…Our IPA identified glutamate degradation, glutamate-dependent acid resistance, GABA receptor signaling, and 4-aminobutryate degradation as systems that were both downregulated following OB surgery and upregulated by HI-rTMS and, to a lesser extent, MI-rTMS. Consistent with our findings, changes in GABAergic and glutamatergic processes in the brain have been reported following OB 59 – 62 and in the brain and blood of depressed patients 63 . Furthermore, rTMS in rodents and in humans can selectively alter GABA and glutamate levels in the brain and blood 64 – 66 .…”

Fish oil improves anxiety‐like, depressive‐like and cognitive behaviors in olfactory bulbectomised rats

“…The antidepressant effect of FO has been attributed to its ability to increase hippocampal BDNF and 5‐HT levels (Venna et al ., ; Vines et al ., ). In fact, the neurochemical data showed that hippocampal levels of 5‐HT and 5‐HIAA, but not 5‐HT turnover, were decreased by Obx, replicating previous studies (Jancsar & Leonard, ; Moriguchi et al ., ; Song & Wang, ). Importantly, FO supplementation in Obx rats reversed the 5‐HT hippocampal deficit induced by the lesion.…”

Neurokinin-1 receptor deletion modulates behavioural and neurochemical alterations in an animal model of depression

“…It should be noted that towards the end of the trial, locomotor activity of OB NK1−/− mice returns to that of wild type counterparts, indicating that, although the substance P/NK1 receptor system may be involved in the initial reactivity of OB mice to a novel stressor, other transmitter systems are likely to also be involved in the altered behavioural responding in the model. Alterations in monoaminergic neurotransmission have been the most widely studied neurochemical change examined in the OB model, with reduced serotonin and noradrenaline functioning (typically measured as steady state neurotransmitter levels) observed in discrete brain regions such as the frontal cortex, amygdala, hippocampus and midbrain [42,62,[80][81][82][83][84][85]. In accordance with these findings, the present study demonstrated that the serotonin metabolite 5HIAA and noradrenaline levels were significantly reduced in the frontal cortex of OB mice.…”

“…In comparison, serotonin levels in the amygdala were increased in OB mice when compared to Sham-operated wild type controls. Methodological differences such as strain/species of animal used, time post surgery, time post behavioural testing and technique used may account for the discrepancy between our finding and those previously reporting reduced serotonin functioning in the amygdala of OB animals [62,82,83]. Chronic antidepressant treatment has been demonstrated to normalise not only many of the behavioural but also the neurochemical changes observed following bulbectomy [for review see [36,37]].…”