Intrinsic excitability of CA1 pyramidal neurones from the rat dorsal and ventral hippocampus.
نویسندگان
چکیده
The hippocampus has a central role in learning and memory. Although once considered a relatively homogenous structure along the longitudinal axis, it has become clear that the rodent hippocampus can be anatomically and functionally divided into a dorsal component generally associated with spatial navigation, and a ventral component primarily associated with non-spatial functions that involve an emotional component. The ventral hippocampus (VHC) is also more sensitive to epileptogenic stimuli than the dorsal hippocampus (DHC), and seizures tend to originate in the VHC before spreading to other brain regions. Although synaptic and biochemical differences in DHC and VHC have been investigated, the intrinsic excitability of individual neurones from the DHC and VHC has received surprisingly little attention. In this study, we have characterized the intrinsic electrophysiological properties of CA1 pyramidal neurones from the DHC and the VHC using the whole-cell current-clamp method. Our results demonstrate that somatic current injections of equal magnitude elicit significantly more action potentials in VHC neurones than DHC neurones, and that this difference stems from the more depolarized resting membrane potential (RMP; 7 mV) and higher input resistance (R(in); 46 M measured from RMP) observed in VHC neurones. These differences in RMP and R(in) were also observed in dendritic whole-cell current-clamp recordings. Furthermore, morphological reconstructions of individual neurones revealed significant differences in the dendritic branching pattern between DHC and VHC neurones that could, in principle, contribute to the lower somatic R(in) of DHC neurones. Together, our results highlight significant differences in the intrinsic electrophysiological properties of CA1 pyramidal neurones across the longitudinal hippocampal axis, and suggest that VHC neurones are intrinsically more excitable than DHC neurones. This difference is likely to predispose the VHC to hyperexcitability.
منابع مشابه
Dorsoventral differences in Kv7/M-current and its impact on resonance, temporal summation and excitability in rat hippocampal pyramidal cells.
In rodent hippocampi, the connections, gene expression and functions differ along the dorsoventral (D-V) axis. CA1 pyramidal cells show increasing excitability along the D-V axis, although the underlying mechanism is not known. In the present study, we investigated how the M-current (IM ), caused by Kv7/M (KCNQ) potassium channels, and known to often control neuronal excitability, contributes t...
متن کاملDiabetes Mellitus Type1 and Neuronal Degeneration in Ventral and Dorsal Hippocampus
Background and Objectives: Studies have documented the morhplogical, neurochemical and functional difference between the dorsal and ventral zones of hippocampus. The aim of this study was to assess the effects of chronic diabetes mellitus type1 on ventral and dorsal zones of hippocampus. Methods: Experimental diabetes was induced by stereptozotocin at a dose of 60 mg/kg. At the end of 8 wee...
متن کاملEffects of resveratrol on intrinsic neuronal properties of CA1 pyramidal neurons in rat hippocampal slices
Introduction: Resveratrol (3,5,4-trihydroxystilbene) a non-flavonoid polyphenol found in some plants like grapes, peanuts and pomegranates, possesses a wide range of biological effects. Evidence indicates that resveratrol has beneficial effects on nervous system to induce neuroprotection. However, the cellular mechanisms of the effects are not fully determined. In the present study, the cellula...
متن کاملDendritic GIRK Channels Gate the Integration Window, Plateau Potentials, and Induction of Synaptic Plasticity in Dorsal But Not Ventral CA1 Neurons.
Studies comparing neuronal activity at the dorsal and ventral poles of the hippocampus have shown that the scale of spatial information increases and the precision with which space is represented declines from the dorsal to ventral end. These dorsoventral differences in neuronal output and spatial representation could arise due to differences in computations performed by dorsal and ventral CA1 ...
متن کاملUse of Colchicine in Cortical Area 1 of the Hippocampus Impairs Transmission of Non-Motivational Information by the Pyramidal Cells
Colchicine, a potent neurotoxin derived from plants, has been recently introduced as a degenerative toxin of small pyramidal cells in the cortical area 1 of the hippocampus (CA1). In this study, the effect of the alkaloid in CA1 on the behaviors in the conditioning task was measured. Injections of colchicine (1,5 μg/rat, intra-CA1) was performed in the male Wistar rats, while the animals were s...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- The Journal of physiology
دوره 590 22 شماره
صفحات -
تاریخ انتشار 2012