Hippocampal Abnormalities of Glutamate/glutamine, N-Acetylaspartate and Choline in Patients With Depression Are Related to Past Illness Burden.

Hippocampal abnormalities of glutamate/glutamine, N-acetylaspartate and choline in patients with depression are related to past illness burden.

J Psychiatry Neurosci. 2013 Mar; 38(2): 107-16
de Diego-Adeliño J, Portella MJ, Gómez-Ansón B, López-Moruelo O, Serra-Blasco M, Vives Y, Puigdemont D, Pérez-Egea R, Alvarez E, Pérez V

Background: Smaller hippocampal volumes in major depressive disorder (MDD) have been linked with earlier onset, previous recurrences and treatment refractoriness. The aim of our study was to investigate metabolite abnormalities in the hippocampus associated with past depressive illness burden. Methods: Glutamate/glutamine (Glx), N-acetylaspartate (NAA) and choline (Cho), potential markers of glial/neuronal integrity and membrane turnover, respectively, were measured in adults with depression and healthy controls using a 3 T magnetic resonance spectroscopy scanner. Voxels were placed in the head of the right and left hippocampus. We controlled for systematic differences resulting from volume-of-interest (VOI) tissue composition and total hippocampal volume. Results: Our final sample comprised a total of 16 healthy controls and 52 adult patients with depression in different stages of the illness (20 treatment-resistant/chronic, 18 remitted-recurrent and 14 first-episode), comparable for age and sex distribution. Patients with treatment-resistant/chronic and remitted-recurrent depression had significantly lower levels of Glx and NAA than controls, especially in the right hippocampal region (p ? 0.025). Diminished levels of Glx were correlated with longer illness duration (left VOI r = -0.34, p = 0.01). By contrast, Cho levels were significantly higher in patients with treatment-resistant/chronic depression than those with first-episode depression or controls in the right and left hippocampus (up to 19% higher; all p ? 0.025) and were consistently related to longer illness duration (right VOI r = 0.30, p = 0.028; left VOI r = 0.38, p = 0.004) and more previous episodes (right VOI r = 0.46, p = 0.001; left VOI r = 0.44, p = 0.001). Limitations: The cross-sectional design and the inclusion of treated patients are the main limitations of the study. Conclusion: Our results support that metabolite alterations within the hippocampus are more pronounced in patients with a clinical evolution characterized by recurrences and/or chronicity and add further evidence to the potential deleterious effects of stress and depression on this region. HubMed – depression


Presynaptic Muscarinic Receptors Reduce Synaptic Depression and Facilitate its Recovery at Hippocampal GABAergic Synapses.

Cereb Cortex. 2013 Feb 20;
González JC, Lignani G, Maroto M, Baldelli P, Hernández-Guijo JM

Hippocampal gamma oscillation, involved in cognitive processes, can be induced by muscarinic acetylcholine receptors activation and depends in large part on the activation of ?-aminobutyric acidergic (GABAergic) interneurons. The precise role of the modulatory action of muscarinic receptors on GABAergic transmission still remains unclear due to the great heterogeneity of observed effects. We have examined the presynaptic and postsynaptic mechanisms involved. Methacholine induces a down-regulation of evoked inhibitory postsynaptic currents (eIPSCs) not associated with the change of postsynaptic receptors. The significant decrease in the paired-pulse depression strongly suggested a presynaptic mechanism of action. We have used cumulative amplitude profile analysis to show that the impairment of eIPSCs is not related to a decreased size of the readily releasable pool, but rather depends on the reduced release probability by a down-modulation of voltage-gated calcium channels. The decreased neurotransmitter release probability only partially accounts for the dramatic reduction in the rate of synaptic depression evoked by short- and long-lasting tetanic stimuli. This effect is accompanied by a significant enhancement in the rate of recovery from synaptic depression that demonstrates the reinforcement of the synaptic recycling processes. These results show that muscarinic modulation of hippocampal GABAergic synapses confers a greater resistance to sustain periods of intense synaptic activity in the gamma frequency range. HubMed – depression


Personality profiles and depression in haemodialysis patients.

Prilozi. 2012 Dec; 33(2): 117-29
Pop-Jordanova N, Polenakovic M

(Full text is available at http://www.manu.edu.mk/prilozi). Chronic haemodyalisis is an established treatment of end stage renal disease which maintains the lives of individuals who otherwise would have succumbed to a uraemic death. However, this method of treatment raises certain psychological, social and ethical issues, where depression and stress are the most common. This article is concerned with the evaluation of depression and the psychologi-cal characteristics of patients treated by chronic maintenance haemodyalisis. Using two psychometric tests (Beck Depression Inventory and MMPI-201) we obtained a signi-ficant incidence of depression (90.63%) in patients recruited from two centres for dia-lysis in Skopje, where even the severe form was unrecognized and untreated. The psychological profiles confirmed hypersensitivity, depressive mood, frequent interpersonal problems, and withdrawal from friends and relatives. Latent aggressiveness could be destructive for their social communications. In order to overcome the depression some response measures such as relaxa-tion training, psychological support, music therapy or peripheral biofeedback are recommended. Key words: haemodyalisis, depressions, personality profiles. HubMed – depression